National Academies Press: OpenBook

Highway Infrastructure Inspection Practices for the Digital Age (2022)

Chapter: Chapter 4 - Case Examples

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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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Suggested Citation:"Chapter 4 - Case Examples." National Academies of Sciences, Engineering, and Medicine. 2022. Highway Infrastructure Inspection Practices for the Digital Age. Washington, DC: The National Academies Press. doi: 10.17226/26592.
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60 C H A P T E R   4 Introduction This chapter documents the uses of and practices for various technologies for inspection of new and existing highway infrastructure assets, as reported by eight state DOTs that demonstrated experience with the technologies. Data collected from the literature review and the survey questionnaire were used to identify state DOTs for further study using the following criteria: • The state’s experience with the use of various technologies for inspection of highway infra- structure during construction and maintenance of assets, • The state’s comprehensiveness and the availability of documents and data, and • The agency staff’s willingness to participate. On the basis of these criteria, 12 state DOTs were initially selected for the case examples. Solicitation for participation occurred through phone calls and e-mails. Then, on the basis of the contacts that were made and the availability of DOT staff, the following eight DOTs participated in the case examples: Florida, Illinois, Iowa, Minnesota, New York, Oregon, Pennsylvania, and South Dakota. Participation involved conducting structured interviews with state DOT staff members who had knowledge of their state’s use of the technologies in question. As needed, the cases were refined by collecting documents and reports, after which the findings were reviewed with state staff members for accuracy. The state DOTs selected for interviews were provided the option to arrange separate or combined interviews about highway inspection during construction versus infrastructure inspection during maintenance of assets (i.e., asset management). Predominantly, the state DOTs opted for combined interviews that, while challenging to complete within a timely manner, added significant value in cross-disciplinary discussion. The interviews conducted separately also held benefits as the discussions reached further specifics in a given subject area. A structured interview questionnaire was used for each case example. The questions were structured around six sections: (1) general information, (2) geospatial technologies, (3) remote monitoring and sensing technologies, (4) mobile devices and software application technologies, (5) nondestructive evaluation technologies, and (6) final thoughts and lessons learned. The case example questionnaires are provided in Appendices C1 and C2. This chapter documents the findings in a similar order as the interview questionnaire for each case example. Florida Department of Transportation The Florida Department of Transportation (FDOT) uses consultants almost exclusively to handle its construction inspection. The use of technologies for construction inspection at FDOT affects the consultants for construction inspection and internal maintenance staff for Case Examples

Case Examples 61   asset management. Currently, FDOT uses all four technology areas studied in this synthesis for construction inspection and asset management: (1) geospatial technologies, (2) remote sensing and monitoring technologies, (3) mobile devices and software applications, and (4) nondestruc- tive evaluation methods. Each of these technologies is summarized in the following sections, along with an overview of the use of the technologies at FDOT for construction inspection and asset management. Use of Technologies for Construction Inspection and Asset Management FDOT implements technologies for construction inspection and asset management on the basis of evaluations of the cost and time of using a specific technology. The ROI is considered when evaluating the use of a new technology, although the current ROI process is performed more informally. If a technology is determined to save costs, time, or labor, that is a big motivator for FDOT to pursue the use of that technology. Along with cost and time, safety is another motivator for FDOT to use a technology. If a technology takes an inspector out of harm’s way and makes for a safer working environment, then FDOT investigates that particular technology for use. Contractors also drive the use of technologies for construction inspection at FDOT. For example, paving contractors that work with FDOT began using AMG several years ago, which pushed FDOT to start developing and piloting the use of 3D models. Along with the use of AMG, FDOT has had two pilot projects where Construction Engineering and Inspection (CEI) con- sultants used GPS rover devices to perform inspections. For asset management and maintenance, the use of technologies is also considered for cost and safety. Technologies are used to track and monitor assets (such as guardrails) that are clas- sified by type so FDOT can monitor and determine maintenance needs. In addition, videos of inspections (such as for drainage) are stored in a GPS database for future use, which also helps FDOT determine maintenance needs for specific assets. Overall, the use of technologies helps FDOT create e-maintenance processes. Geospatial Technologies Application for Highway Inspection During Construction FDOT uses GPS, UASs, terrestrial photogrammetry, and e-ticketing. GPS rovers are used by consultant construction inspectors and are range poles with a GPS unit attached to them, along with a tablet that allows the inspector to measure aspects of a project and collect location data in three-dimensional space. In addition, the GPS rovers were able to communicate with the contractor base station for one of the pilot projects, which helps ensure accuracy when using the technology tool. GPS is also used for locating soil borings. UASs with photogrammetry are used by consultant inspectors, primarily for taking aerial photographs to track progress, albeit in a currently informal approach. The UAS flies the project at specific times (e.g., monthly) and the photos that are taken are compared with one another to visually see the progress of the work and whether it appears correct based on the plans and specifications. Furthermore, FDOT is currently exploring the use of UASs with photogrammetry to take actual measurements and quantify materials. UASs have also been used in a limited capacity for official surveys to check the work that is put in place. E-ticketing is used by FDOT, primarily for asphalt material deliveries to construction sites. FDOT had already been moving toward the use of e-ticketing for a few years, but the COVID-19

62 Highway Infrastructure Inspection Practices for the Digital Age pandemic accelerated its implementation and use. A few projects had been piloted with e-ticketing prior to the pandemic, but because of pandemic restrictions, FDOT had to find ways to reduce the physical presence of on-site staff and eliminate the need to physically collect tickets, which was not allowed on jobsites during the pandemic. Contractors were a driving force for the use of e-ticketing during the pandemic, as many began purchasing e-ticketing software packages and a few even developed their own e-ticketing systems. This implementation from the contractors’ side helped FDOT move toward expanded use of e-ticketing. Application for Highway Infrastructure Inspection During Maintenance of Assets GPS and GIS, as well as UASs in specific situations, are used for FDOT’s e-maintenance system. GPS and GIS are used to locate and map assets across the state, which are used with their e-maintenance system. UASs are employed for bridge inspections for asset and maintenance purposes that help maintenance crews investigate all areas of a bridge, including the areas that are hard to reach or that put a person in an unsafe situation. UASs are also used to assess damage of assets after a disaster, such as a hurricane. Assessing damage using UASs allows FDOT to make quick decisions on the necessary repairs. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction FDOT uses LiDAR, remote sensors, infrared sensors, and remote cameras for various types of construction inspections. For example, infrared sensors are used to monitor temperatures for mass concrete pours and for drilled-shaft construction work, which is related to thermal integrity testing. LiDAR is used for earthwork tasks and measuring quantities for construction inspections. Remote cameras are used on construction sites, and the consultant inspectors use the cameras to visualize the progress of work over a specific period of time. Remote cameras are also used in construction for special activities, such as sliding in a bridge to its permanent location from the construction location, in order to document the operations. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, FDOT is exploring the use of barcodes and readers, specifically for sign inventory. Similarly, LiDAR is being investigated for drainage assets, as LiDAR can be used to see where the drainage is going. FDOT mentioned that discussions are taking place on expanding the use of LiDAR for construction and maintenance. Specific applications of sensors and cameras are the monitoring of rest area assets and number of available parking spaces, and the maintenance aspects required for the Skyway bridge in Tampa, FL. In rest areas, FDOT placed sensors in the pavement to note whether a parking space is occupied or not. Remote cameras visually show which spots are available for truckers to use. This helps the traveling public and improves FDOT’s operations. Stress and strain gauges, along with accelerometers, are placed along the Skyway bridge to monitor its movement. Monitoring the bridge remotely helps maintenance determine the bridge’s needs without inspectors physically having to measure and check movement on a regular basis. Finally, FDOT mentioned that it has a robust IT system that includes video cameras on limited access roadways. When crashes occur, maintenance can make informed decisions on repairing the infrastructure and associated equipment prior to visiting the site.

Case Examples 63   Mobile Devices and Software Applications Application for Highway Inspection During Construction For construction inspection, FDOT has implemented the use of 3D engineered models, AMG, tablets and smartphones, and handheld rover devices. FDOT is currently piloting projects in which the 3D model is developed by FDOT and provided to the contractor for AMG purposes. Handheld GPS/RTK devices are used by consultant inspectors for inspecting AMG work. FDOT is developing guidance for its staff in this area. Tablets have been used by field inspectors for a few years with some success, in that information can be collected and documented in real time and in a digital format that is easy to share. How- ever, FDOT has run into the challenge of tablets not handling the heat well and getting damaged, and tablets are not cheap to repair or replace. Maintenance personnel also have tablets with apps for collecting information on assets that then feeds into their GIS system. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, FDOT has an e-maintenance system, which is an initiative to have a more precise inventory of highway assets by using GPS and GIS technologies. The e-maintenance system is envisioned to be an inventory tracking and monitoring tool as well as a tool for capturing spe- cific features that can be reviewed and inspected in an automated fashion. The e-maintenance system has been implemented in phases, the first of which has used the system for locating and mapping guardrail approach terminals and crash cushions across the state. For example, the e-maintenance system not only takes the inventory of guardrail approach terminals and crash cushions, but also includes information on when a guardrail approach terminal or crash cushion was impacted in a crash and what damage and injuries resulted when it was hit. This system feed- back may be automated by smart devices or captured from traffic operations cameras. Figure 4.1 shows an example of an e-maintenance system used by FDOT. FDOT expects that future analysis of these data will help them determine what systems, end- treatments, and crash cushions perform the best. Phase two of the e-maintenance system is to move toward similar aspects of e-construction as in phase one, but for maintenance and asset management. The processes will be digitalized and will use electronic forms, moving away from a paper-based system. The e-maintenance system also includes SAM, which is FDOT’s storm water asset mainte- nance system. Furthermore, a new initiative is taking the inventory of FDOT’s highway lighting Figure 4.1. An example of FDOT’s e-maintenance system (courtesy of FDOT).

64 Highway Infrastructure Inspection Practices for the Digital Age assets. Future enhancements within the e-maintenance system will include inventorying rest areas and weigh-in-motion stations. Specifically, for rest areas, the system can track informa- tion like the number of available parking spaces, what toilets are functioning, and what needs to be repaired. The next phases will also include inventory and inspection for signs, inventory of guardrails as a statewide system, and more. The e-maintenance system helps FDOT know what assets it has across the state and where they are located, and smart information can be embedded within the assets in the system. Further implementation of the e-maintenance system is ongoing, and FDOT plans to use the e-maintenance system for all aspects of maintenance and asset management in the near future. Beyond taking inventories, the e-maintenance system will incorporate smart components to augment inspection and provide live system feedback. All statewide users of the e-maintenance system have mobile devices and applications (ArcGIS and Survey123) to feed data into their GIS approach. Nondestructive Evaluation Methods Application for Highway Inspection During Construction Nondestructive evaluation methods are used in construction and include use of ground- penetrating radar (GPR), surface profiling, dynamic test loading for piles, ultrasonic testing, thermal integrity tests, cross-hole sonic logging for drilled shafts, falling weight deflectometers, nuclear density gauges, and acoustic emissions. Because of the geologic makeup of Florida, GPR is used during paving operations when the vibrations of the rollers may activate surface depressions and sinkholes. GPR is then used to check and see what kinds of subsurface repairs are needed. GPR is also used to check the locations of reinforcing steel in bridge decks. As mentioned, thermal integrity testing is used in conjunction with cross-hole sonic logging for drilled shafts during construction. Surface profiling is used to check the smoothness of pave- ments. Ultrasonic testing is used to check steel connections and welds. Application for Highway Infrastructure Inspection During Maintenance of Assets The FDOT interviewees mentioned that FDOT uses GPR for initial sinkhole investigations on existing roadways. However, use of nondestructive evaluation methods for highway infrastruc- ture during maintenance of assets is limited. Lessons Learned FDOT uses a variety of technologies for construction inspection and asset management. FDOT’s lessons learned in use of these technologies include: • Technology durability—FDOT has experienced issues with mobile technologies not being durable and rugged enough to handle the harsh conditions of an FDOT jobsite. Specifically, FDOT has found heat to be a significant issue when using mobile devices such as tablets to collect data in the field. FDOT has mitigated the issue using a variety of techniques, but there has not been a systematic solution to the issue. The result is frustration, technology damage, and loss of time to allow the technology to cool, which then results in a loss of the potential efficiencies gained in using the technology. • Maintaining the technology and associated equipment—Technology for construction inspec- tions and asset management is not cheap, and if not maintained, the technology’s capabilities can become limited. FDOT realizes that it needs to support and maintain its equipment so personnel can perform their responsibilities correctly and efficiently. • Compatibility of technologies—FDOT has experienced incompatibility issues, such as incom- patible GPS rovers that cannot communicate with the contractor’s base station, which have

Case Examples 65   led FDOT toward a statewide network that broadcasts correction information for those devices instead of communicating with the base station. Overcoming incompatibilities has been a challenge, but FDOT has found different ways to address these issues and also requires specific technologies in the contracts so consultant inspectors will provide equipment that is compatible with the systems in place. Illinois Department of Transportation The Illinois Department of Transportation (IDOT) has been undertaking rapid develop- ments in its construction and asset management systems over the past 5 years. This trend is a continuation of the transitioning that began in the past decade to move away from mainframe- type management systems and into more agile, accessible, and available web-based technology systems. IDOT uses an assortment of technologies that feed data into both the legacy and the advancing web-based systems for both construction and asset management. These technologies cross a spectrum of the four technology areas studied in this synthesis: geospatial technologies, remote sensing and monitoring technologies, mobile devices and software applications, and nondestructive evaluation methods. The following sections summarize the key findings of these technologies related to highway infrastructure inspection based on the discussion with IDOT. Use of Technologies for Construction Inspection and Asset Management IDOT’s use of technology is driven by a host of factors, including the desire to be more efficient, to use data more effectively, to make data more accessible, and to modernize its legacy systems. In both construction and asset management, IDOT has a desire to modernize its systems and move toward web-based solutions. A decade ago, IDOT fell far behind in technology use and relied on mainframe systems, but it has been making significant advancements, especially in the past 5 years. For construction, IDOT does try new technologies that look promising or have been success- fully used by other states, yet it typically does not mandate their use. Instead, IDOT accommo- dates the implementation of new technologies by finding contractors interested in participating in pilots with them. For asset management, IDOT has also been working toward the use of new systems and technologies while cautiously protecting the validity of its legacy data during the migration to new systems. IDOT’s confidence and comfort in existing practices, especially in asset management, has led to slower adoption of new technologies. With too much of its data being collected through the previous paper-based approaches, IDOT believes electronic processes offer opportunities for instant efficiencies, although these opportunities present challenges to consider as well. IDOT noted that procurement is one significant challenge to implementing new technolo- gies. IDOT highlighted that determining the approach needed to procure a technology and also learn how to implement it into workflows and data collection processes is lengthy and compli- cated within a government agency. Implementing new technologies may also have ripple effects because of needed updates to policies, testing methods, or even legislation, before a full transi- tion to a new technology can take place. Nonetheless, IDOT sees value in being able to collect and analyze its data in more streamlined approaches. When adopting new technologies, like many states, IDOT does not have a formal evaluation approach and uses anecdotal evidence to determine whether pilots and trials of technology have

66 Highway Infrastructure Inspection Practices for the Digital Age been effective. IDOT accounts for costs in procuring and maintaining the new technologies when considering the value attained. IDOT acknowledges that it can be difficult to validate the data collected through technology, and IDOT often requires duplicative efforts to capture data in traditional approaches as well as with the piloted technologies. This method is necessary to evaluate the costs and accuracy of the new approach. These cost comparisons include traditional approach costs, costs for consulting the work, costs for hardware and software, and maintenance costs of the new approaches. IDOT makes decisions on technology use on the basis of judgments of costs and value, with an understanding that an updated and accessible data system can have value not readily realized. Geospatial Technologies IDOT uses GNSS/GPS, GIS, and RTSs. It is also exploring the use of UAS and e-ticketing. The role of geospatial technologies for IDOT has been to improve efficiency in both construction and asset management areas. Application for Highway Inspection During Construction For construction inspection, IDOT crews use GPS rovers and RTSs, primarily Trimble systems, to perform project layouts and check alignments and grades as construction is performed. While not programmatically implemented, UASs have been used to collect photos and videos of project sites. While this UAS use may be performed by the contractor in most instances, IDOT does have a division of aeronautics with UASs capable of performing these activities. IDOT’s investigation into e-ticketing has been based on the reception of its contractors. Where contractors have been receptive or have even promoted its use, IDOT has collaborated with vendors and the contractor to implement e-ticketing on a project-by-project basis. As new vendors continue to enter the market, IDOT will still require paper tickets if the vendors are not comfortable with the e-ticketing system being used. IDOT is not moving toward a require- ment to use e-ticketing, but it feels this technology will become the industry standard because of the benefits the technology provides to both the contractor and the state agency. IDOT noted that, in general, procuring technologies can be very difficult in a government agency. This is especially true in construction where the owner of the specified technology could be IDOT or its construction contractor. The policies and specifications controlling these pro- curements can be problematic when piloting technology on a project-by-project basis. Addi- tionally, IDOT noted that staff training and use of the technology presents challenges, as change in general is not always welcome. In fact, learning new technologies is sometimes viewed as a distraction even if efficiencies are an expected outcome. Nonetheless, IDOT sees technology implementation as necessary to cope with staffing reductions and collect data in an efficient and usable method for improved decision making now and in the future. Application for Highway Infrastructure Inspection During Maintenance of Assets IDOT’s use of GIS for asset management is quite mature, as it began using that technology in the 1990s. In fact, GIS, complemented by the use of GPS, is the primary tool for asset collection. IDOT uses GIS with its pavement assessment data to create georeferenced shapefiles to share pavement smoothness (using the international roughness index) and rutting information. GIS is also used to share other forms of IDOT data. The publicly available Illinois Roadway Analysis Database System (IROADS) shares pavement conditions, the multiyear highway improvement plan, traffic counts, and more. This system, along with dashboards sharing roadway performance metrics, has been very well received, especially by the Metropolitan Planning Organiza- tions (MPOs) in Illinois. As mentioned, IDOT has been using GIS since the 1990s, but it is

Case Examples 67   currently procuring and working toward a significant system transition to the Deighton’s Total Infrastructure Management System (dTIMS) infrastructure asset management software system. It is also investigating the use of UASs for bridge and pavement inspections. IDOT noted that there are several challenges in developing the GIS linear referencing for its system and in keeping it updated. The linear referencing of the roadways is the backbone of the GIS system. As the IDOT roadway system changes, the linear referencing must be kept up to date. Another challenge is also related to system benefits. IDOT noted that the amount of data being collected for the GIS system is great, but the storage, access, and analysis of that amount of information presents unique challenges. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction For construction inspection, IDOT noted that the use of remote sensing and monitoring tech- nologies is determined on a project-by-project basis. IDOT has used LiDAR and 3D scanners for construction on occasion, but IDOT uses them more frequently in design. Another use of remote monitoring in construction includes using sensors to monitor vibration or noise in proximity to buildings or urban areas where construction could cause nuisance or property damage. IDOT frequently uses remote or web-enabled cameras and Smart Work Zones during construction of a highway project. IDOT has used remote and web-enabled cameras for visu- ally monitoring projects and progress as well as their associated effects on traffic. IDOT employs remote sensing technologies for Smart Work Zones. These technologies can be used for moni- toring traffic flow, indicating accidents in the work zone, minimizing delays with adaptive signage, and monitoring for work zone intrusions. Additionally, IDOT noted that it does not mandate the use of intelligent compaction, but some of its contractors have piloted the use of the technology on hot mix asphalt paving projects and IDOT saw promise in the technology. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, IDOT used the mobile LiDAR system for the statewide collection of various assets along the National Highway System and state-managed routes. This was part of IDOT’s pavement condition assessment, but IDOT coordinated this assessment among other divisions to collect asset grade data for other features. These features include structure widths and heights, clearance heights of any overhead obstructions (e.g., sign trusses, traffic signals, and structures), a sign inventory (roadway signs and billboards), and an inventory of guardrail and cable barriers, among other items. This approach, conducted in 2017 and 2018, collected a vast amount of data and served many users. IDOT is currently refreshing this data through the same approach but is planning to collect additional features where possible, such as the retro- reflectivity of signs. IDOT’s challenge has been in how to best share the data collected and incor- porate it into existing workflows. IDOT’s approach has been to share the data with GIS since it is provided in a geotagged format. Other remote sensing technologies used by IDOT for highway inspection during asset management include vehicle-mounted cameras for pavement condition assessment and IDOT’s system of remote cameras. For example, the system of remote cameras can be used to monitor assets related to traffic operations, signal timing, heavy commercial vehicle counts for pavement condition projections, and rest areas. This system of cameras can also be accessed for construc- tion purposes when projects are nearby. IDOT notes that these remote sensing and monitoring technologies save time and provide value with their data collection and access capabilities, but IDOT faces challenges in the volume and sharing of the data generated by these technologies.

68 Highway Infrastructure Inspection Practices for the Digital Age Mobile Devices and Software Applications Application for Highway Inspection During Construction For construction inspection, IDOT has been working with 3D models for some time, but it is not providing these models as the record contract document. The developed 2D or 3D model is communicated between the IDOT design division and construction division according to their computer-assisted drafting manual so it can be used with the rovers and total stations for checking grade or other project features. The developed 2D or 3D model is sometimes shared with the construction contractor, but not as a contract document. Typi- cally, IDOT found that the construction contractors re-create their own models from the shared electronic project data. The IDOT construction field staff is typically equipped with laptop computers, iPads, or iPhones. These devices are being used for various data collection based on IDOT’s Construc- tion and Materials Management System (CMMS). The system is web-based and will manage measurement and payment, manage construction documentation, or change documentation. Other handheld devices used in construction by IDOT include handheld data collectors (Trimble devices), which are used with IDOT’s rovers and RTSs. These devices are procured through statewide purchases for the field crews for survey and data collection. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, the IDOT staff also uses laptops, tablets, and smartphones, although some have resisted this transition and still collect information manually. These mobile devices are used for updating roadway and other asset inventories, and in some cases, IDOT has forms prepared within the ArcGIS Collector application for assessments, such as the collection and assessment of Americans with Disabilities Act (ADA)-related assets. It is noted that IDOT currently does not have a central repository for the ADA information, so the use of this method is district- to-district and in urban settings. There are several challenges for IDOT in using these technologies. For example, the tran- sition from the comfort of the traditional process to using new technologies can be difficult. IDOT noted that inspectors often have concerns about the time it takes to learn new methods or technologies, even if they provide long-term time savings. It has been a challenge for IDOT to make sure that those doing inventories are aware of the electronic option for conducting the work. Additionally, IDOT noted that procuring, providing training for, and implementing new technologies in a government agency is difficult since the technology will always change faster than the DOT can react. Nondestructive Evaluation Methods Application for Highway Inspection During Construction For construction inspection, IDOT uses nondestructive testing technologies in many aspects of highway construction projects. IDOT uses cross-hole sonic logging and thermal integrity profiling for the random checking and inspection of their drilled shafts under con- struction. IDOT will sometimes test the driven structural piles with dynamic load testing using the Pile Driving Analyzer System. In pavements, IDOT has used surface profile mea- suring systems and inertial profiling systems for rutting and roughness index assessments. Nuclear density meters have also been used for asphalt pavements, but density is core verified. IDOT is currently exploring the use of magnetic imaging tools for verifying dowel bar place- ment in concrete pavement.

Case Examples 69   Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, nondestructive testing methods are also used, but to a lesser extent than during construction. A falling weight deflectometer has been used by IDOT’s Bureau of Research on occasion for pavement evaluation. IDOT has also tested a rolling weight deflec- tometer. Additionally, IDOT is using a vendor to provide surface profiling with a Laser Crack Measurement System (LCMS) capable of providing pavement assessment, crack measurement, rutting assessment, and more. Lessons Learned IDOT’s experiences with technologies provided opportunities to share lessons learned. The following are highlights of key lessons learned in using technologies for highway infrastructure inspection: • Evaluation of technology used—IDOT does not have a formal evaluation approach for con- sidering technologies but believes that the decision to use a technology should not be solely cost-based. There is also an evaluation of the data collected. For instance, the Laser Crack Measurement System (LCMS) used by IDOT provided data that align with federal perfor- mance metrics requirements. • Challenges in change—IDOT noted that, no matter how beneficial a technology may be, a transition from comfortable processes with traditional approaches could meet resistance, especially if a time commitment will be needed for new training or implementation. IDOT stated that it takes a champion to maintain the momentum behind these types of changes and a belief that the outcome of the new technology will be beneficial. • Data collection and migration—A challenge noted by IDOT is in regard to data already col- lected. Not only can the volume of new data collected by technology present a challenge, but the connection of these data with an existing data set can also present a challenge. Legacy data may be difficult or costly to transfer, and in some cases it may not even be in a digital or digi- tized form. Conversions and migrations of this type of data need to be handled with caution to ensure that the intent and understanding of the data are well communicated. IDOT noted that its databases are becoming more complicated and are being moved from databases managed and well-understood within a specific business unit to more centrally managed IT systems. IDOT notes that the knowledge of the data collected and of how it should be reported must be well communicated and validated. IDOT also notes that this concern is exacerbated by knowledge loss through attrition. Iowa Department of Transportation The Iowa Department of Transportation has been progressive in technology implementa- tion for construction and asset management inspection for several years. With technologies such as e-ticketing and GIS-based asset inventories, the Iowa DOT is commonly looked to as a benchmark by many other state DOTs. This case example highlights the technologies that the Iowa DOT employs in the four technology areas studied in this synthesis: geospatial technolo- gies, remote sensing and monitoring technologies, mobile devices and software applications, and nondestructive evaluation methods. The following sections summarize the technologies, benefits, and challenges discussed with the Iowa DOT. Use of Technologies for Construction Inspection and Asset Management The Iowa DOT noted that there have been many driving forces behind its implementation of technologies. These driving forces range from industry requests to reductions in staffing.

70 Highway Infrastructure Inspection Practices for the Digital Age In the area of GIS use, federal protocols and the need to track various performance metrics provided the impetus for some of the Iowa DOT’s inventory and inspection modules, but internal requests from field staff members led to initial module development. In 2010, a district main- tenance manager’s request for a paperless inventory and inspection system for culverts that allowed for mobile data collection started the Iowa DOT on its path of developing GIS modules. The success of this system led to the creation of others. The Iowa DOT continued to develop varying modules for data collection and now has dozens of applications for maintenance and construction inventory and inspection of new and existing assets. This innovation led to other advances in its asset management approach. In construction inspection, the industry has often been the driving force behind innovation for the Iowa DOT. GPS and machine control usage are examples of where the industry was driving the innovation. The McAninch Corporation had significant experience with machine controls and AMG in its commercial projects and made a request to the Iowa DOT to use the technology in its highway projects. This led to a successful pilot and continued use of the approach on a case-by-case basis. The Iowa DOT noted that innovation has also come from research. Its first use of machine controls for paving was part of a research project. The initial pilot showed that the technology was available but the industry was not adopting it yet. The research project in 2012 provided pilot opportunities, and the experience led to adoption of the technology by the industry. Both construction contractors and technology vendors have helped lead the innovation and use of new technology for streamlining the Iowa DOT’s processes. When more efficient means have been demonstrated, the Iowa DOT sees value and need for the technology because of what could be the Iowa DOT’s largest driving force to technology implementation—reductions in staffing. Workloads and reduced staff numbers present a need for efficiency, which is where technologies can add significant value. In construction inspection, the Iowa DOT is using a combination of laptop computers and iPads but is testing the use of Microsoft Windows–based tablets to replace this combination. The Iowa DOT noted that Windows tablets, as mobile devices, still have GPS capability, which allows for collection of data for the asset management and GIS system with fewer limitations in the availability and support of applications than those found in the Apple devices. Geospatial Technologies Application for Highway Inspection During Construction For construction inspection, the Iowa DOT is using GPS and GNSS, UAS, GIS, and e-ticketing. The Iowa DOT has a limited number of survey-grade GPS units that provide accuracy through RTK corrections using Iowa’s Real-Time Network, a continuously operating reference stations (CORS) system. These GPS devices are used for checking quantities, measuring items and dis- tances, referencing project stations and offsets, measuring cuts and fills, and more. These devices may also be used to complement mobile devices in the collection of asset grade data for entry into GIS systems. As part of the Iowa DOT’s as-built process, data are processed in the inventory and asset management system as they are collected for signs, culverts, roadway tiles, and other features. Iowa DOT contractors also use RTSs for machine-controlled paving, and the Iowa DOT inspection staff is provided access to these stations and GPS rovers to check measurements and quantities. The Iowa DOT noted that it is not using UAS to the extent it would like. Each of the Iowa DOT’s districts has UASs, but they are currently only using the UASs for project photos and videos. The Iowa DOT is investigating the software and applications necessary to use photogrammetry features and LiDAR devices to facilitate the creation of surfaces and 3D models from the data

Case Examples 71   collected using UASs. By gaining the ability to make measurements and do inspections with the data, the Iowa DOT will be able to use these data for more than simply visuals, such as for erosion control. The Iowa DOT is actively using UAS pictures and photogrammetry provided by a consultant for a major river-crossing bridge, which is demonstrating the technology’s ability to provide measurable models as well as asset management inside (the structural arch) and outside the structure. This same approach is being piloted in three other projects, and the information is being geospatially tagged for the assets. Iowa has been a pioneer and leader in the use of e-ticketing. The Iowa DOT piloted this tech- nology heavily, conducting 94 projects in 2020, using several different vendors. The Iowa DOT noted that the use of multiple vendors has been one of the challenges of using e-ticketing. As a result, the Iowa DOT is working toward the creation of a central hub that would be able to accept e-ticketing data from all vendors and provide for adoption of the data into the workflows for their AASHTOware construction management system, DocExpress (document management system), Appia (project dashboards), and GIS systems. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, the geospatial technologies are fundamental to the Iowa DOT’s GIS system. The data within the Iowa DOT’s GIS are mostly mapping grade as there is minimal survey-grade data collection. Most of the Iowa DOT field offices are GPS-enabled but not all of them have the equipment to collect data using GNSS and RTK corrections. The Iowa DOT asset management also employs UASs for photographing and inventorying assets at rest areas and maintenance yards or garages. The Iowa DOT noted several challenges with geospatial technologies, including the manage- ment of data and technology from multiple vendors, lapses in cellular coverage, duplicative efforts while piloting technology, and simply keeping up with technological advancements. The Iowa DOT noted that lapses in cellular coverage can be a challenge with geospatial technologies because in addition to their use as mobile devices, some GPS receivers require connectivity for corrections. The Iowa DOT is investigating the use of cellular service boosters for projects where they are experiencing issues with lapses in coverage. The Iowa DOT also notes a challenge in just keeping up with the technology hardware and software advancements. Trying to keep up with the hardware and software also creates the workforce challenges of keeping up training and knowledge in the technology being used, in addition to making sure the hardware and software are updated. This is especially a challenge across multiple vendors and platforms. Another chal- lenge is the constant evolution of the Iowa DOT’s workforce. Adding, dropping, and modifying user access to keep everyone up to date is a significant challenge when using the number of modules and systems employed by the Iowa DOT. Yet another challenge in adopting technolo- gies is the duplication done when piloting these new approaches. When the Iowa DOT pilots a new technology, such as the use of GIS-based as-built documents, the Iowa DOT actually completes both the traditional paper-based approach and the technology-based approach. It is necessary for the evaluation process, but duplicative work is not welcomed by the field staff completing it. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction The Iowa DOT does employ some standard uses of remote sensing and monitoring technolo- gies, but many of the technologies in this area are being piloted. As standard practice, the Iowa

72 Highway Infrastructure Inspection Practices for the Digital Age DOT uses barcodes and mobile applications as readers for a few of its approaches to data col- lection and tracking. An example of barcode use in construction is the GIS tracking and logging of asphalt cores and samples. The Iowa DOT’s main challenge with use of barcodes has been in deployment and training of the technology. Another remote sensing and monitoring technology in use is intelligent compaction (IC). The Iowa DOT is using IC for geotechnical investigations only, and still on a pilot project basis. The collected data are mapped using a web-hosted service. Several other remote sensing and monitoring technologies are implemented or piloted on a project-by-project basis. Remote sen- sors such as accelerometers, strain gauges, thermal sensors, and motion detectors have been employed on the Iowa DOT’s ongoing Mississippi River crossing major project. These specific deployments have limited construction purposes and are largely installed for future asset man- agement, but construction staff has found them to be useful at times. The Iowa DOT has conducted some pilot projects using thermal profiling of asphalt pave- ments and, in conjunction with its ongoing e-ticketing efforts, has experimented with remote cameras for object recognition (for confirmation of haul truck identification numbers) to pro- vide verification measures of asphalt delivery. Some of the Iowa DOT’s experimentation has been met with the previously mentioned challenge of a lack of cellular coverage. The Iowa DOT also noted that, while it has not used LiDAR to a large extent in construction, it does see promise in the technology, especially in the option of adding LiDAR to a UAS. Application for Highway Infrastructure Inspection During Maintenance of Assets Handheld LiDAR is being employed in asset management to share the location and volume of salt stores for deicing. The Iowa DOT has only one of these devices, and it is shared with the staff on location and in environmental offices as well. The Iowa DOT is considering an upgrade of this device since they have noted its potential benefits, but it is not GPS-enabled nor survey grade. The Iowa DOT currently has the ability to tie the data collected to mapping through benchmarks or targets within the data of a known location. Mobile Devices and Software Applications Application for Highway Inspection During Construction The Iowa DOT substantially uses mobile devices and software applications for highway construction inspection. The Iowa DOT’s use of 3D models starts in its design divisions. While still experimenting, the Iowa DOT has had projects where the 3D model was the con- trolling contract document. The Iowa DOT has seen success in these projects and is moving toward Building Information Modeling (BIM) for infrastructure on the basis of its experi- ence. It has an upcoming pilot project to test the use of an all-electronic plan set (with paper backup). The Iowa DOT’s steps to move to models and paperless construction are supported by its industry. While its field staff is not always well equipped for inspection using models, the Iowa DOT’s projects that employ models and AMG require their construction contrac- tors to provide access to rovers and necessary services for inspecting grades, distances, or points. The handheld devices used by construction staff in Iowa commonly include iPads and, in some cases, iPhones. The staff has been testing Microsoft Windows tablets because a particular module of the Iowa DOT’s AASHTOware construction management system is not supported on Apple devices. In addition to these devices, the Iowa DOT construction staff has access to survey data collectors with capability for RTK corrections.

Case Examples 73   Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, the majority of the mobile devices used for inspection of infrastruc- ture assets are iPads and iPhones, with many of the applications used being developed in-house. These applications are focused on the asset’s auxiliary to the Iowa DOT’s official asset manage- ment plan, which focuses solely on roadway and structure assets and their condition. These in-house-developed applications collect inventory and inspection data for culverts, drainage systems, traffic barriers (including cable, concrete, steel, and crash cushions), fences (manmade and living snow fence), patching and repair locations, lighting systems (poles, hand holes, and cabinets, along with tracking the underground utility paths), ADA features at intersections, signs and posts, native vegetation plantings, erosion control, geological assessments, and striping and symbol painting. The Iowa DOT is also using applications to track underground utility paths at maintenance facilities to the edge of their properties, and for the Iowa Communications Network to track conduits, hand holes, and cabinets. The Iowa DOT noted that application developers also produced several geospatially enabled forms and applications, such as the barcode reader for tracking asphalt cores. The collected information feeds into a web portal and can be accessed by mobile devices. The data are held on secure servers and are not cloud-based, so it is necessary to log in. The Iowa DOT has used cloud services in the past but found that data syncing between multiple clouds and the DOT’s own servers created many challenges for reporting data, especially for dashboards and live reporting. The Iowa DOT is actively working to migrate all of its data to data warehousing systems where it can be analyzed. The DOT plans to use this analysis for preparing feature reporting and dashboards. These efforts are supported by the DOT’s information technology group, which is housed within the Iowa DOT, as well as a team of developers and IT database staff members with a GIS focus within their operations group. The Iowa DOT has experienced numerous challenges in implementing mobile devices and software applications. Foremost, one of the challenges mentioned by the DOT pertained to the rapidly changing technology in this environment. Changes and elimination of software plat- forms or new hardware create a constant state of flux and require the Iowa DOT to continuously evolve and change. These changes involve ripple effects for providing guidance and training to the field staff using the technology. The Iowa DOT noted that each change brings about addi- tional challenges. For instance, the DOT’s data migration resulted in unexpected system out- ages. Communicating that changes are occurring can help prepare staff for possible problems, since the communication once an outage has occurred is difficult. Another challenge comes with success. The Iowa DOT noted that keeping up with demand for new applications and bringing these applications online with correct protocols and standards is challenging, especially with limited staff to work on these applications. Without a standard asset management approach or data governance, as is currently the case, the Iowa DOT attempts to tie everything to its linear referencing system (the road network), which will allow for future analytics when there is a desire and when staff have the availability to do so. Nondestructive Evaluation Methods Application for Highway Inspection During Construction The Iowa DOT noted that nondestructive evaluation methods tend to be used on a case-by- case basis. The Iowa DOT also noted that it uses cross-hole sonic logging for drilled shafts and dynamic load testing for piles, and that it uses nuclear density gauges, but only for soil density in specific soil types. On occasion, the Iowa DOT has used GPR for determining the location of

74 Highway Infrastructure Inspection Practices for the Digital Age steel reinforcing and determining the extent of concrete deterioration. The Iowa DOT has also used magnetic imaging tomography scanners for verifying reinforcement placement in concrete and has started to use them to confirm asphalt and concrete pavement depths. The Iowa DOT mentioned the use of falling weight deflectometers for design purposes, the use of ultrasonic scanning through preliminary research, and the use of reflectometers for testing reflectance of striping and signs. Application for Highway Infrastructure Inspection During Maintenance of Assets The only noted use of nondestructive evaluation technology for inspection of infrastruc- ture assets was in using GPR to locate the Iowa DOT lighting and operations conduits as part of projects’ One Call requests. Use of these types of technologies for asset inspection and condition assessment would potentially occur during the development of maintenance repair projects. Lessons Learned On the basis of their experience in the use of inspection technologies, the Iowa DOT noted several lessons learned, summarized as follows: • Enhancing innovation—The Iowa DOT has found that innovation may come from multiple sources, such as the DOT’s industry partners or research. For example, while the vision for e-ticketing was initially started within the Iowa DOT, the DOT’s contracting community sees the value in the technology and promoted its advancement. Similarly, although the initial pilot of AMG for paving did not provide desirable accuracy, adjustments and continued test- ing improved the accuracy and achieved industry buy-in. • Evaluation of technologies—Similar to other state DOTs, the Iowa DOT evaluates the new technologies and innovations using an anecdotal approach. The Iowa DOT is willing to try technologies that show promise but then evaluate continued use on the basis of consider- ations of contract administration burden, time and effort, and long-term goals, among others. For the Iowa DOT, costs are an evaluation factor, but these are weighed against the value provided and the value of having the data. For the Iowa DOT’s asset management, the ability to make data-driven decisions in terms of allocating spending on repairs and replacements is valuable. • Keep up to date and benchmark—The Iowa DOT noted that it is challenging to stay up to date with hardware and software. While the Iowa DOT considers itself to be on the leading edge in some areas, it understands that any lapse in its approach to continued improvement puts it behind. However, the Iowa DOT also looks to other state DOTs to learn, benchmark, and leverage its experiences. The Iowa DOT notes that with technology you cannot be afraid to fail and you cannot become complacent. Continuous improvement is needed to be at a high level of innovation. • Technology changes rapidly—The Iowa DOT noted that technologies change rapidly. In a short window of 5 years, the Iowa DOT went from experimental implementation of e-ticketing with two vendors to having many vendors, and they are moving toward a portal- style hub to collect data to manage the varying sources. This is a trend in technology and the Iowa DOT’s approach has been to pilot what they can and learn from others when first- hand testing is not possible. The DOT’s participation in webinars, presentations, and peer exchanges provides ample opportunities to learn from others. • Specification challenges—The Iowa DOT noted that there is a challenge of preparing specifications for technology implementation. The Iowa DOT found that it is difficult to specify the needed technologies and get the contracting community updated on the objective of using a particular technology when conducting a pilot. If the specification

Case Examples 75   does not lead to the purchase and application of the correct technology for a pilot, the opportu- nity may be lost. Minnesota Department of Transportation The Minnesota Department of Transportation (MnDOT) implements technologies for the inspection of construction work and infrastructure assets. MnDOT uses geospatial technologies, remote sensing and monitoring technologies, mobile devices and software applications, and nondestructive evaluation methods for construction inspections, while asset management uses geospatial technologies, remote sensing and monitoring technologies, and mobile devices and software applications. The sections below outline the use of these technologies for construction inspection and asset management at MnDOT. Use of Technologies for Construction Inspection and Asset Management MnDOT began using 3D building information modeling, which initiated the investigation and use of further technologies throughout the agency. Then MnDOT took steps to advance the use of 3D models and digital construction delivery by bringing in knowledgeable staff members to implement their use, which upper management supported. Since the initial implementation of 3D modeling, districts in Minnesota have initiated the use of various technologies for con- struction and asset management. For example, one district within MnDOT is providing training on technologies for inspections. Additionally, MnDOT is working on a project to establish a process for inspectors to document information for pay items using 3D models. In implementing the use of a technology for asset management, MnDOT realized that it needed an enterprise level of utilization of advanced technologies. MnDOT developed a strong data governance model that included collaboration throughout the agency. Then MnDOT created an asset management program office in the planning department. The asset manage- ment program office provides support, training, and practices on ancillary asset inspections. MnDOT used research and national best practices to promote and implement asset man- agement inspections for bridges and pavements throughout the state. Furthermore, MnDOT partnered with Minnesota Information Technology Services (MNIT) to explain roles and responsibilities, develop clear service models, and collaborate to meet the IT staffing needs for developing and supporting the use of technologies. In having the MNIT agency as a partner, MnDOT is able to explore and use technologies more efficiently. Implementation of innovative inspection methods is very important to MnDOT. One driving force is the reduction of time spent performing inspections by maintenance staff and instead having increased asset repair time. MnDOT has documented time savings for metro inspection crews when using GIS field devices versus paper-office data entry, and has found that GIS field devices have improved data accuracy. MnDOT also documents the efficiencies in using tech- nologies by instructing district offices and specialty areas to document before and after business processes to record any efficiencies. Safety is also a concern for inspections as most traditional, boots-on-the-ground field inspec- tions occur near fast-moving traffic. For example, instead of an inspector just describing a crack by a condition rating and comment, the actual crack can be seen in a 3D model. Furthermore, as stated by one MnDOT employee, by providing personnel with a handheld device in lieu of non-digital tools and equipment, staff members are able to be more aware of their surroundings and provide for safer efforts to perform their work.

76 Highway Infrastructure Inspection Practices for the Digital Age Geospatial Technologies Application for Highway Inspection During Construction MnDOT currently uses geospatial technologies for construction inspection (including GPS and handheld RTK devices for measuring quantities and assisting with developing as-builts), UASs for bridge inspections, RTSs for inspections and verification, photogrammetry for mea- suring quantities and progress, and e-ticketing for digitally tracking materials. Pavement work at MnDOT includes profile milling. To implement this, MnDOT provides the digital model to contractors to mill according to the model, rather than telling them to mill 1 or 2 inches. To inspect the profile milling, inspectors use RTSs to verify the milling. As men- tioned by MnDOT staff members, the profile milling process has provided smoother pavements and contractors are becoming more efficient at milling, resulting in a better product for MnDOT and the traveling public. MnDOT invests time and resources into its e-ticketing initiative. Using e-ticketing removes individuals from harm’s way because a person then does not have to navigate through heavy machinery to collect tickets as materials are brought to the site and placed, and the information is transferred digitally to MnDOT. Also, MnDOT more accurately tracks all loads coming out of plants that make it to the project. Additionally, with the COVID-19 pandemic, the ability to collect tickets electronically instead of physically handing tickets to one another helped with social distancing measures that were in place on projects during this time. Currently, MnDOT is leading an effort to develop the industry standards around the use of e-ticketing. The benefits of using geospatial technologies for construction inspection are better efficiency, improved accuracy, and the ability to remove individuals from hazardous situations. Inspection technologies are tied to the 3D models that MnDOT develops, and the plan is to continue to develop MnDOT’s use of technology for feeding information to and from inspectors in order to improve construction performance. The challenges in using geospatial technologies for con- struction inspection have been the initial implementation and the legal and engineering hurdles that have to be cleared. Application for Highway Infrastructure Inspection During Maintenance of Assets Most of MnDOT’s infrastructure assets have been located using GPS technology, and field crews add inspection data to the asset record. MnDOT uses GIS to share condition and inspec- tion data for planning and scoping purposes. Using GPS and GIS for asset management allows for quick and easy documentation from a map-based field application for both internal and external inspectors. Geospatial technologies provide clear data on asset locations and conditions that MnDOT shares with external agency partners for maintenance agreements and consultant projects. UAS technology has been used for bridge inspection in places that are difficult to reach or areas that are hazardous. The MnDOT bridge office has been involved in determining the return on investment and benefits to using UASs for bridge inspections. UAS technology has also been piloted for locating and mapping supplementary assets such as entrance monuments and earth- retaining structures in order to obtain real-world 3D digital models of these assets for use in inspections, as well as for developing future monuments and retaining structures. Challenges associated with geospatial technology use for asset management include keeping GPS/GIS data current and the pushback from employees about using technologies. Tracking construction and maintenance activities, costs, and changing conditions for 1.5 million assets across the state requires staff members and substantial amounts of their time. It is also the

Case Examples 77   perception of some personnel that the technologies are too hard to figure out, that traditional means work just fine, and that there is no time to learn an innovative technology tool. Yet, as MnDOT has realized, overcoming these challenges with staff members has pushed them to be more digital with their projects and provides better data for construction and asset management. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction Remote sensing and monitoring technologies used by MnDOT for construction inspections include LiDAR, intelligent compaction (IC), remote sensors, infrared sensors, and remote cameras. IC has been employed by MnDOT during construction and used for quality assurance inspections. MnDOT found that IC helps with coverage measures but is not necessarily good for density measures. MnDOT uses maturity on concrete projects, and infrared sensors are used for thermal profiling during paving. Thermal profiling has proven to be an efficient and accurate tool, and MnDOT is increasing its use on construction projects. Remote cameras are used for traffic management at construction sites and for monitoring progress of the work. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, MnDOT employs LiDAR and remote sensors. MnDOT conducted a statewide mobile LiDAR project in 2018 that inventoried more than 12 asset classes to determine locations and attributions. The project utilized boots-on-the-ground inspectors to inspect the performance of traffic barriers, including the identification of defects. This project also mea- sured bridge clearance using LiDAR with the results used as a secondary data set for the physical inspection of as-built data. Remote sensors for asset management are used in health monitoring systems to validate original design assumptions. The largest health monitoring system installed is on the I-35W bridge replacement in Minneapolis. Other projects used for research purposes include health monitor- ing systems using remote sensing strain gauges for load testing. In addition, remote sensors are used to monitor slope movements near existing assets. Challenges mentioned by MnDOT related to asset management and the use of remote sens- ing and monitoring technologies include the limited service life of strain gauges, filtering and interpreting large amounts of data, dealing with false negative results when using technologies for testing, obtaining the right expertise to install and calibrate sensors, and establishing accu- rate tolerances. Mobile Devices and Software Applications Application for Highway Inspection During Construction MnDOT uses 3D engineered models, AMG, tablets and smartphones, and RTK handheld devices for construction inspection. The use of 3D engineered models and AMG has been driven by the contractors that work with MnDOT, which has helped MnDOT advance in these technology areas. Using 3D models and AMG-equivalent inspection technologies provides inspectors with real-time data that are easy to access on the tablet they have in the field. Inspectors also use a collector app on tablet devices when conducting field inspections. Handheld rover devices are provided to inspectors to collect data on specific aspects of a project. The challenges that MnDOT experiences with using mobile devices and software applica- tions are incompatibility issues, training staff, and keeping device hardware current. Internally,

78 Highway Infrastructure Inspection Practices for the Digital Age different departments and offices use different software and mobile devices. Externally, con- tractors may use different software and mobile devices as well. Finding common or universal files to share data tends to cause issues in some cases. Personnel need to be trained so that they use the mobile devices and associated software properly and accurately, as well as for changes in the processes they perform. For example, MnDOT staff mentioned that surveyors may spend more time in the office today than they did in the past, processing and analyzing data, which is a change for experienced surveyors who used to spend most or all of their time in the field. Keeping devices current can be expensive when replacing technologies on a regular basis as the technologies continue to improve. However, the use of mobile field devices at MnDOT provides the benefit of real-time and accurate data collection, improving the efficiency of inspection operations. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, MnDOT uses 3D engineered models, tablets and smartphones, and handheld devices. MnDOT is not currently inspecting assets within operations and maintenance using 3D engineered models. However, a large pilot project in District 3 is ongoing in which hydraulic asset data are being used for design and a digital twin is used to track through con- struction and back to maintenance and asset management. The digital twin will allow MnDOT to recognize more accurate costs for assets and pay items for contractor work, and to update the model to recognize the real-time changes made to a physical asset. MnDOT has used Windows mobile field devices for over 10 years to collect asset information. In the past 4 years, MnDOT has moved to tablet devices and smartphones in the field (paired with a receiver if needed) to apply field devices for multiple needs, such as phone calls, e-mail, or network access. A challenge mentioned by asset management personnel in the use of 3D models is that a project design may include important project information that is passed to construction for use so proper as-builts are developed for below and above the ground for projects. Nondestructive Evaluation Methods Application for Highway Inspection During Construction In construction inspections, MnDOT uses GPR, surface profiling, dynamic test loading for piles, ultrasonic testing, cross-hole sonic logging, falling weight deflectometers, nuclear density gauges, infrared thermography, and magnetic imaging tools. For surface profiling, RTSs are used to measure surfaces and provide data for inspections and proper surface preparation. Dynamic test loading is used on large scope projects to test piles for structures. Ultrasonic testing has been used to check internal concrete and rebar conditions for work placed during colder months. As stated by MnDOT staff members, issues related to voids in materials have been found using ultrasonic testing that would not have been found using more traditional inspection tools, which is helping improve construction quality. Cross-hole sonic logging is used when drilled shafts are called for in a structure. Nuclear testing gauges are used occasionally, and contractors are using them for quality control purposes. However, the strict processes to maintain and use nuclear testing gauges limit their use by MnDOT, and other traditional methods are used to avoid the maintenance of nuclear testing gauges. Magnetic imaging tools (MITs) are used to check reinforcing steel alignments for concrete projects. MITs have been helpful for inspections to make sure reinforcing steel is correct, as

Case Examples 79   steel misalignment causes joints to crack and increases the maintenance needs of that particular asset. MITs are used as a specification to be used by contractors on specific MnDOT construc- tion projects. Application for Highway Infrastructure Inspection During Maintenance of Assets MnDOT utilizes GPR, surface profiling, and a variety of nondestructive evaluation meth- ods for inspection of assets. GPR is commonly used to locate reinforcing steel in concrete bridge elements prior to drilling or coring, and it is periodically used for bridge deck evalu- ations. GPR has been a valuable tool for MnDOT in locating reinforcing steel prior to drilling or coring. MnDOT also uses GPR coupled with infrared thermography for deck evaluations. However, inconsistencies have been found when using GPR and infrared thermography for deck evaluation, so it has not been implemented statewide and further investigation is ongoing. Surface profiling may be required by MnDOT following the surface preparation of steel ele- ments and prior to painting. Surface profiling is also used following the surface preparation of concrete surfaces and prior to placing polymer overlays or concrete repair material. In both cases, the surface profiling helps ensure that the surface is prepped to the level it needs before the application of materials. For asset management, MnDOT uses ultrasonic testing, including phased array ultrasonics, liquid penetrant testing, alternating current field measurement (ACFM) devices for crack detection, and magnetic particle inspection for inspecting steel structures to determine the presence of a defect when visual inspection either suggests the existence of a crack or is not sufficient to verify the structural integrity of the element. The most common use of ultrasonic testing is testing pins for the presence of internal cracks. Ultrasonic testing can be valuable to ascertain the internal condition of structural elements that cannot be visually inspected. However, MnDOT has experienced challenges in using nondestructive evaluation methods, as field conditions sometimes vary significantly from ideal equipment tolerances, and the equipment needs to be accurate to ensure that the data collected are also accurate. Lessons Learned MnDOT uses a variety of technologies for construction inspection and asset management. Lessons learned by MnDOT in the use of these technologies include: • Leadership support—Gaining leadership support has helped MnDOT move forward with implementing technologies for construction inspection and asset management. Having a champion (whether an individual or an office within the agency) for a particular technology also helped MnDOT explore and advance the use of technologies for inspections and asset management operations. • Safety—The use of e-ticketing helped MnDOT eliminate the need for personnel to be walking around moving heavy equipment during pavement operations. The use of handheld devices in the field helps inspectors be more aware of their surroundings. The use of technologies that can provide safer inspection and asset management practices is important to the operations performed at MnDOT. • Staff knowledge and availability—In order to explore, test, and implement a specific tech- nology for construction inspection or asset management, MnDOT recognized that having the right staff members that possess the training and knowledge, as well as having enough resources available, make a positive difference for implementing technology use.

80 Highway Infrastructure Inspection Practices for the Digital Age New York State Department of Transportation The New York State Department of Transportation (NYSDOT) uses a variety of technolo- gies for highway inspection during construction and asset management. These technologies help NYSDOT be more efficient in its work. The technologies used at NYSDOT for con- struction inspection and asset management include geospatial technologies, remote sensing and monitoring technologies, mobile devices and software applications, and nondestructive evaluation methods. The key information related to NYSDOT’s use of these technologies for highway inspection, as discussed with NYSDOT staff members, is detailed in the following sections. Use of Technologies for Construction Inspection and Asset Management Part of the impetus to use technologies for construction inspections comes from contrac- tors that ask to use specific technologies such as AMG. Traditional inspection’s means of using a slope board and level takes too much time. Therefore, in the case of AMG, NYSDOT employs GPS, RTSs, and digital levels to inspect construction work. Another technology that NYSDOT contractors are pushing is UAS. Currently, NYSDOT is limited in its direct use of UASs, but consultants, vendors, and contractors can fly UASs and NYSDOT works with these entities to provide UASs and associated flights when needed. For asset management, tracking and monitoring all the assets across the state is a challenge. To overcome this challenge, NYSDOT has implemented technologies such as surface profiling and UASs. Consultants annually drive all NYSDOT highways and roadways to check the condi- tions of the pavements using a specialized vehicle that has high-resolution cameras and sensors mounted to it. The data collected are fed into onboard computers to check the roughness and conditions of the pavements. The high-resolution photos are taken frequently as the vehicle moves and are then provided in a viewer that inspectors use to “virtually” drive the highway. Maintenance of cracking and pavement repairs are based on these reviews, which helps NYSDOT make decisions on what needs to be repaired and maintained on an annual basis. Without the use of these technologies, NYSDOT would not be able to gather information for all pavements across the state in a timely manner and it would not be as accurate. Evaluating technologies at NYSDOT prior to widespread use includes assessing technologies that are to be used to satisfy federal requirements. In addition, NYSDOT needs to determine how to properly use the data collected from the technologies. Pilots are used to test out technolo- gies in different situations and conditions. Sometimes informal return on investment and cost– benefit analyses are conducted to determine the worth of a technology. NYSDOT noted that it takes time to scale up on the widespread use of technologies. It is important to have information showing the value of technologies to provide proof that NYSDOT can start to implement more widespread use of the technologies. In addition, regional evaluations are conducted to see which regions are willing to implement a technology. Geospatial Technologies Application for Highway Inspection During Construction Geospatial technologies include a range of modern tools that contribute to the geographic mapping and analysis of construction project sites and associated activities. NYSDOT uses GNSS/GPS, GIS, UASs, RTSs, and terrestrial photogrammetry for construction inspections. NYSDOT is also beginning to explore the use of e-ticketing through initial pilot projects, but this technology has not yet been extensively used at NYSDOT.

Case Examples 81   For construction inspections, NYSDOT uses RTSs and digital levels to check specifica- tions on a project (see Figure 4.2). GPS is used along with these tools to accurately locate the specific aspect of a construction project. Along with the use of GPS, GIS is gaining traction on the construction side, as using this technology helps distribute information more easily to different department units and contractors. GIS is more robust; it allows for adding more attributes; and it is easier to use without converting files, as GIS files are more compatible than other file types. Terrestrial photogrammetry is conducted by the NYSDOT photogrammetry department and is used for monitoring construction and the progress of work through the use of UASs. NYSDOT has a 5-year lease plan in place for equipment, which includes RTSs, GPS devices, digital levels, and terrestrial LiDAR units, and this equipment is currently used throughout the state, across its 11 regions. However, items such as the terrestrial LiDAR are stored at the central office and are deployed when necessary for monitoring construction work. Having a leasing agreement provides NYSDOT with a way to continue to improve and increase its use of technologies in inspections by using current and up-to-date equipment. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, NYSDOT has been using GPS and GIS over the past several years. GPS devices are used to determine locations of assets that are then developed into GIS files that are used internally and externally by contractors and consultants. As mentioned by NYSDOT staff members, geospatial technologies are commonly used in conjunction with remote sensing technologies. For example, UASs are often used with LiDAR or photogrammetry to fly and accurately track assets. NYSDOT uses handheld RTK devices that provide accurate location information, which is converted to GIS files and added to the GIS portal. One challenge in using geospatial technologies in inspections and asset management is having the right people with the right skills using the technologies. Other challenges include the cost of equipment and discrepancies between contractor and NYSDOT reference stations. However, the NYSDOT representatives acknowledged that they are trained to help address and overcome these challenges. Having staff members that understand the processes of using technologies helps create fairness and solve issues in the field between contractors and inspectors. Figure 4.2. Robotic total station (RTS) in use on I-95 in Manhattan (courtesy of NYSDOT).

82 Highway Infrastructure Inspection Practices for the Digital Age Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction For construction inspection, NYSDOT uses LiDAR, RFID, IC, remote sensors, infrared sensors, and remote cameras. NYSDOT noted that inspectors use LiDAR for wall monitoring, roadway deviations, emergency situations, bridge clearances, and getting point clouds from construction to asset management. Figure 4.3 shows terrestrial LiDAR being used by NYSDOT for rock excavation work. Figure 4.4 illustrates the point cloud obtained from using LiDAR. Contractors on construction sites are beginning to use mobile LiDAR to monitor and track the progress of the work compared with the design and specifications. RFID tags are used in spe- cific situations at NYSDOT depending on the utility group and the project type. IC is sometimes used by NYSDOT for specific approach slabs and subbase placement of roadways, as IC pro- vides information on undercompaction and overcompaction of materials placed. The geotech- nical group uses remote sensors for dynamic pile testing and slope monitoring on construction projects. Data collectors used with survey equipment have laser range finders that help gather specific measurements. Remote cameras are used for major projects in New York City and other parts of the state to monitor progress remotely. Finally, on the construction side, NYSDOT is beginning to explore the use of barcodes and readers for collecting personnel and equipment information remotely from a project site. One of the newer remote sensing technologies being piloted for use in construction inspections on major construction projects is a 360-degree high-resolution camera. An entire 360-degree view of the jobsite can be taken through multiple photos, and this view is then uploaded to a soft- ware program that creates a point cloud from the photographs. The point cloud captures a visual description of what has been placed, which then allows NYSDOT to compare the point cloud to the design model and the critical path method (CPM) schedule simultaneously to check for any discrepancies, for adherence to the project schedule, and for proper locations of the work. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, NYSDOT employs LiDAR and various remote sensors to track, monitor, and maintain assets across the state. NYSDOT noted that LiDAR and remote cameras in use for asset management are used with vehicles by a contracted third-party consultant. The system has high-resolution cameras and mobile LiDAR to check the conditions of pavement on all Figure 4.3. Terrestrial LiDAR in use for rock excavation (courtesy of NYSDOT).

Case Examples 83   NYSDOT highways and roadways throughout the state. The consultant uses artificial intelli- gence on the collected data from the cameras and LiDAR to provide NYSDOT with linear feet of cracking across five different zones. The photo log, which includes high-resolution photos taken by the vehicle every 26.5 feet and GPS coordinates for the location of each photo, is provided in a viewer that allows one to virtually drive the road and see the actual cracking data as they scroll along the bottom of the screen. In addition, the pavement condition data are important for asset extraction. Asset extrac- tion of signs, sidewalks, sidewalk ramps, drainage structures, guiderails, and rumble strips was performed using the geopositioning of the high-resolution photo log pictures and by implementing artificial intelligence to extract the assets. This system does not provide a spe- cific point cloud but helps NYSDOT in its inventorying of assets, which include pavements (pavement type, number of lanes, shoulder information), sign structures, sidewalks, drainage structures, rumble strips, noise walls, and retaining walls. The accuracy of the data collected from the cameras is within 2 feet when traveling at 65 miles per hour, which is exceptional for NYSDOT in tracking and monitoring NYSDOT’s asset inventory. Once the assets are extracted, NYSDOT can then distribute the asset information to the proper department. For example, the safety department is notified regarding the data collected on rumble strips to check the quality and maintenance needs of these assets. Furthermore, NYSDOT has piloted the use of mobile LiDAR for asset extraction, but the cost currently outweighs the widespread use of mobile LiDAR. A challenge mentioned by NYSDOT in the use of LiDAR and sensing devices is that the data collected are only for information within the line of sight. Furthermore, tying assets back to the linear referencing system can be a challenge because assets have to be manually added to road- ways, such as signs and guardrails. Limited IT resources are also a challenge in implementation of remote sensing and monitoring technologies. Figure 4.4. Point cloud from LiDAR for rock excavation (courtesy of NYSDOT).

84 Highway Infrastructure Inspection Practices for the Digital Age Mobile Devices and Software Applications Application for Highway Inspection During Construction Mobile devices and software applications in use for construction inspections include 3D engineered models, AMG-equivalent inspection equipment, tablets and smartphones, handheld RTK devices, VR/AR, and various mobile apps and software programs to col- lect, view, and analyze the data collected with the mobile digital devices. NYSDOT noted that 3D models are used along with a BIM specification on large design-build projects. The specifi- cation requires the contractor to update the 3D model throughout the project and produce 3D as-builts and 3D GIS models at the conclusion of the project. Currently, NYSDOT is implementing 4D and 5D models that allow the project staff and management to account for and verify time and costs associated with overall project schedules as well as specific components of a project. The majority of contractors are using AMG on projects because it makes work more efficient and NYSDOT is able to inspect AMG work using technologies. All construction inspectors have a tablet or laptop and a cell phone, including in-house and external third-party consultant inspec- tors. Handheld data collectors are used with RTK GPS units for collecting data on inspections and progress of work, and they note the actual location of the work being inspected. NYSDOT is testing out a simplified GPS system that can be connected to a tablet or smartphone. The accuracy may not be survey grade, but it is acceptable for construction purposes. Furthermore, NYSDOT has a virtual reality and augmented reality department, which is part of the design department. In construction, the virtual and augmented reality information is used to develop 4D and 5D animations to illustrate the work progress. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, NYSDOT noted that a system of engagement in NYSDOT enables the use of asset-centric viewers that permit anyone within NYSDOT to view the information collected on assets in NYSDOT’s asset management system. The viewers provide the NYSDOT staff with information about assets, including items such as accurate location, pavement conditions, and the previous 3 years of maintenance history from NYSDOT’s maintenance management system. Feedback from NYSDOT staff members shows that the viewers are very helpful and provide better information and accuracy than previous methods used. Along with the viewers, NYSDOT is also developing specific asset class applications that can be used on smartphones and tablet devices to keep the geospatial warehouse of asset information updated. Nondestructive Evaluation Methods Application for Highway Inspection During Construction For construction inspections, nondestructive evaluation methods are typically conducted by specific groups or departments within NYSDOT and are not necessarily performed by con- struction staff members. The groups performing these inspections using nondestructive evalu- ation methods include the technical services group, geotechnical group, and pavement group. GPR is used to look for underground utilities, inspect conditions of pavements such as voids in bridge decks, and locate the edge of concrete pavement with an asphalt overlay. The use of GPR is performed by the technical services group at NYSDOT. Surface profiling has been used on construction projects where issues arise in the conditions of the pavement. Using surface profiling provides evidence to contractors that there is an issue and that they are responsible for correcting the issue. Color coding in the surface profiling highlights the locations that are out of tolerance and need to be corrected.

Case Examples 85   Dynamic test loading for piles is used by NYSDOT for inspections. The geotechnical group at NYSDOT is in charge of conducting cross-hole sonic logging on all drilled-shaft construc- tion work and performing inspections using the falling weight deflectometer. Contractors are required to use nuclear density gauges and provide reports back to NYSDOT for inspection and review on every paving project. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, NYSDOT noted that a high-speed GPR is being piloted and that the use of this technology is possible, but the costs are very high considering that this technology is not needed across the state. Additionally, surface profiling is used and developed from high- resolution camera images that are taken from the vehicles for all NYSDOT roadways across the state. Surface profiling is taken width-wise across a roadway, which provides information about the roughness and rutting of a pavement asset. That information helps NYSDOT make decisions about the maintenance of a particular roadway. Lessons Learned NYSDOT uses a variety of technologies for inspection of highway infrastructure during construction inspection and asset management. Lessons learned by NYSDOT in the use of these technologies include: • Work with contractors—NYSDOT noted that its contractor base has pushed NYSDOT to use more technologies for inspection. The use of 3D models, AMG, photogrammetry, UASs, and LiDAR was driven by contractors employing these technologies. Furthermore, NYSDOT had to modify its processes to use these technologies effectively for inspections to match the effectiveness of how contractors are using them. • Researching the technologies—When a new inspection technology is introduced at NYSDOT, the thought process is that someone else is probably exploring or using the technology already. Rather than creating and developing its own ways of using a technology, NYSDOT looks to other agencies and even contractors to see how they use it, and that becomes the starting point to develop the processes for internal use. There is more than one option and vendor for these technologies, and it is important for NYSDOT to find the option that best matches its business operations. • Training requirements—NYSDOT realized that using technologies correctly requires training. Additionally, NYSDOT observed the benefits of providing training to employees regularly to learn the technology as well as refresher training to keep inspectors up to date. • Interdepartmental cooperation and coordination—Data collected during different phases of project development need to be compatible for use in other departments within NYSDOT in order to enhance coordination across the departments. Oregon Department of Transportation The Oregon Department of Transportation (ODOT) has advanced the use of technolo- gies throughout the department in recent years. For construction inspections, ODOT is using geospatial technologies, including GNSS/GPS and UAS; remote sensing technologies such as LiDAR, tablets and smartphones in the field; RTK handheld devices, 3D models, and AMG; and various nondestructive evaluation methods. For asset management, geospatial technologies and LiDAR are used extensively, along with mobile devices and different software applications that are accessible with a smartphone or tablet in the field. Further details of these technologies are discussed in the following sections.

86 Highway Infrastructure Inspection Practices for the Digital Age Use of Technologies for Construction Inspection and Asset Management In the past 10 years, ODOT has developed internal divisions that manage the exploration and implementation of technologies for construction and asset management. In 2010, a 25-year automation plan was developed at ODOT by visionary leaders to map out future technology use for various processes at ODOT, including infrastructure inspections during construc- tion and asset management. This plan led to the establishment of the engineering automation section, which plays an important role in implementing technologies at ODOT. The engineering automation section includes the geometronics unit (formerly photogrammetry unit), which is made up of remote sensing and UAS programs, right-of-way engineering, geodetic surveying, and engineering technology advancement. ODOT realized the need to have a centralized group that can consult on technology efforts, although data collected using technologies are somewhat isolated in different divisions and units of ODOT. However, before the engineering automation section was established, technology efforts were isolated as well, and the engineering automation section helped ODOT be more collaborative statewide. In addition, ODOT mentioned that technologies were evaluated qualitatively in the past. However, ODOT is now implementing technology steering processes to analyze costs, technical factors, and other issues. Typical considerations include expectations of in-house expertise, staff time requirements, what data should be collected, where and how to store the data, how technol- ogy eliminates or changes another process, and the subscription and maintenance costs for the technology. Most of the technologies used at ODOT started small, and their use was driven and expanded by end user demands. Furthermore, ODOT has hired consultants and worked with universities to conduct return on investment evaluations of specific technologies. For example, as stated by ODOT, Oregon State University was contracted to investigate the automation and technology concept and expected return on investment for mobile LiDAR. On the basis of the research product, it was determined that ODOT would need to use the mobile LiDAR on 12 to 15 projects a year to be cost-effective. Geospatial Technologies Application for Highway Inspection During Construction The geospatial technologies used by ODOT for construction inspections include GNSS/ GPS, UAS, and robotic total stations (RTSs). In addition, ODOT is starting to explore the use of e-ticketing to improve the tracking, exchanging, and archiving of materials tickets. For GPS use, ODOT has a statewide GNSS network that is used for a variety of tasks, includ- ing construction inspections. GNSS enables RTK handheld devices to provide survey grade accuracy. Tablets with GNSS antennas are used by inspectors to check lines and grades and measure quantities in real time. As stated by ODOT staff members, the software that ties with GNSS is easy to use, and ODOT trains all inspectors to use the software and associated field equipment. UAS use for construction inspections at ODOT includes taking videos, checking elevation data, tracking progress, and verifying payment quantities. UASs provide the construction staff with volumetric information, point clouds, and orthomosaics. In addition, UASs are used for geotechnical work to monitor slides near construction sites and create surface models that are then used with ground-based radar to track the movement of slides. RTSs are used for most surveying and inspection processes on ODOT projects. RTSs are used to monitor construction, stake the project, measure quantities, and check vertical clearances. Consultants also employ RTSs when using AMG, after which the data are provided to ODOT

Case Examples 87   for inspection. Furthermore, ODOT uses RTSs when GNSS is not working or has only limited connectivity because of mountainous areas. Application for Highway Infrastructure Inspection During Maintenance of Assets Asset management at ODOT has been using the GNSS network for 15 years for tasks such as taking inventory of culverts and signs, after which the GNSS location data are fed into ODOT’s asset GIS system. ODOT is now in the process of replacing its current mapping grade handheld devices with survey-grade units that are tied to the GNSS network. The data collected from the inventory of assets are then stored within the individual divisions of ODOT that manage those assets. Along with GNSS, GIS is also used to inventory the ODOT highway assets across the state. The use of GNSS and GIS enables ODOT to be accurate in its tracking and monitoring of its inventory of assets. Finally, UASs are used for asset management, but only to measure material stockpiles at ODOT material locations. There are several challenges in using geospatial technologies at ODOT. As mentioned pre- viously, one limitation is the use of the GNSS network in mountainous terrain. Limited connection or no connection still occurs in some areas, which does not allow for the use of the GNSS network. The connectivity issues affect asset management more than construc- tion. Another challenge for ODOT is determining how to contractually require contractors to use geospatial technologies and provide appropriate data to ODOT for inspection purposes. Additionally, it is important to evaluate the effective use of technologies by proving the worth of these technologies, the costs to purchase and update or upgrade equipment, and the change from a linear reference system based on mile markers to a coordinate correct system based on actual positions. ODOT noted that it may get pushback against the use of a technology at first because inspec- tors perceive that the technology will complicate their tasks and that it will take longer to com- plete their work. Proof of concept needs to be conducted to show the value and efficiency in using these technologies. Cost is a concern, and ODOT continually looks for grants and other resources to help offset the costs of purchasing the required equipment and updating it as the technologies advance. Moving from a linear reference system for locations to GNSS and a coor- dinate correct system has been difficult, but ODOT mentioned that a benefit from the coordinate correct system is that the geospatial positions can be used on more than a static straight-line chart. In summary, as stated by ODOT, the benefits of using geospatial technologies for construction inspection and asset management outweigh the challenges as technology saves resources for ODOT to use on other important work. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction For construction inspections, ODOT has used various technologies, including LiDAR, IC, remote sensors, remote cameras, and barcodes. For example, LiDAR and laser scanning are conducted post-construction by ODOT to verify the final product components such as eleva- tions and clearances by comparing them to the original plans and layout. LiDAR is also used for inspections when paired with other technologies. LiDAR and RTSs are used in conjunction when inspectors need to collect data on a portion of a project that requires remapping. ODOT is also exploring the use of LiDAR with UASs as a tool to track and monitor progress during construction. As mentioned by ODOT staff members, the use of LiDAR during construction helps eliminate issues with contractors by providing data that capture what is happening on a more timely basis.

88 Highway Infrastructure Inspection Practices for the Digital Age Remote sensors, including accelerometers, maturity meters, and stress/strain gauges, are used in construction inspections, mainly on a trial basis, and are not used statewide. One example provided by ODOT is that it uses sensors with bridge projects that might be susceptible to slides. These sensors monitor conditions around the bridge as well as the vertical and horizontal movement of the bridge. Infrared sensors (e.g., thermal profiling) are used by ODOT for paving projects. Using infrared sensors helps inspectors know if the correct materials are being placed in the correct conditions. It is noted that ODOT no longer uses IC. The ODOT representative mentioned that ODOT began exploring the use of IC several years ago. As IC was used, ODOT realized that the infor- mation being provided was not accurate enough and that the costs and resources needed outweighed the benefits. At the time, ODOT paused its IC use until the technology could be improved. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, LiDAR is considered to be a primary tool to acquire data in order to track, monitor, and inventory assets across the state. Mobile LiDAR is acquired on ODOT roadways throughout the state. It is on a 2-year cycle in which the west half of the state is scanned in 1 year and the east half of the state is scanned the next year. The mobile LiDAR data are used to measure bridge heights and clearances and to map locations of assets and driveway approaches. Aerial LiDAR is also used by ODOT to help manage its material assets and stockpiles. Similar to its use for construction, LiDAR is used collaboratively with other technologies, such as using mobile LiDAR to check striping on roadways. Furthermore, ODOT noted that it has used UASs, LiDAR, orthophotography, handheld GNSS devices, and barcodes to investigate and locate potential hazardous trees from the recent wildfires that could affect ODOT roadway assets, as well as to tag tree stumps for auditing (see Figure 4.5). After the devastating September 2020 wildfires that affected the state of Oregon, ODOT was charged with assessing the hazardous trees left behind after the fires. Using UASs and remote sensing tools, ODOT has mapped and assessed thousands of trees across the state in spring 2021. ODOT has realized that more hazards are found and mapped with fewer crews using remote sensing with this asset management inspection process. This allows for better Figure 4.5. Handheld GNSS device showing the location and information of hazardous trees (courtesy of ODOT).

Case Examples 89   efficiency in clearing the hazardous trees before they cause additional damage to ODOT road- ways in the wildfire-affected areas. A challenge that ODOT is experiencing with the use of remote sensing technologies is in the use of a combination of technologies to perform tasks. For example, ODOT has a vehicle that collects a video log of assets across the state, which provides a virtual view of assets. Then, a second vehicle uses mobile LiDAR to check and track assets. However, the idea of combining the two into one has led to new issues. Each vehicle is managed by different divisions within ODOT, and funding and other aspects are different from one division to the other. ODOT is currently working to find a solution for this challenge. Another challenge with the use of remote sensing technologies is the cost to purchase and upgrade equipment once it is outdated. Additionally, a certain level of knowledge and exper- tise is needed to use remote sensing technologies. If the inspectors are not trained to use the technology correctly, the information collected is not valuable and may be incorrect. Storage of information has also become a challenge, as ODOT has terabytes of data that need to be screened and stored properly. ODOT is currently working to improve this issue. Mobile Devices and Software Applications Application for Highway Inspection During Construction For construction inspections, ODOT develops 3D models, which also include digital stamps from engineers. Contractors use the 3D models for AMG on construction projects. ODOT has realized that contractors have become sophisticated in their use of AMG and that projects using AMG tend to be less expensive and faster to construct. ODOT has created specifications for AMG and 3D models along with survey requirements and grade verifications. The information from AMG is then supplied to ODOT for inspection. In addition, the data from AMG during construction are provided to operations and maintenance for asset management. At ODOT, most inspectors use smartphones or tablets to take photos and document work, as mobile applications are connected with ODOT’s construction management software system. Some inspectors have tablets with GNSS antennas for real-time and location-based inspections. In addition, RTK handheld devices that tie into the GNSS network are also used by inspectors during construction to verify specifications and correct placement of work. Application for Highway Infrastructure Inspection During Maintenance of Assets ODOT uses the tablets with GNSS antennas and RTK handheld devices to collect data and location information for culverts, signs, and bridges. One of the benefits of using the mobile devices and software applications mentioned by ODOT is that ODOT is able to collect location- based data in real time that are accurate and usually easy to check and verify during inspection processes. Similar to the use of other technologies, the main challenge of using mobile devices and soft- ware applications at ODOT is gaining buy-in from the staff and inspectors and assisting them with the changes in their processes to incorporate these technologies into their daily tasks. Nondestructive Evaluation Methods Application for Highway Inspection During Construction ODOT uses several nondestructive evaluation methods for construction inspections. GPR, surface profile measuring, falling weight deflectometers, nuclear density gauges, thermal integrity

90 Highway Infrastructure Inspection Practices for the Digital Age testing, and infrared thermography are all used by ODOT for construction inspection purposes. GPR tends to be used for project development to check for burial grounds and archaeological sites as well as to verify pavement depths and bridge work to check reinforcing steel placement during construction. Surface profiling is used by ODOT for paving projects. Nuclear density gauges are used on all paving construction projects at ODOT. Application for Highway Infrastructure Inspection During Maintenance of Assets Compared with construction inspection, ODOT uses nondestructive evaluation methods less frequently for inspection of highway assets. ODOT noted that surface profiling and fall- ing weight deflectometers are used in asset management. Surface profiling is typically used for assessing and managing pavement conditions of assets during operations and maintenance. The falling weight deflectometer is also used for pavement assessment. One of the main challenges in using nondestructive evaluation methods at ODOT involves the mixed use of the technology. The ODOT representatives noted that many of the nondestruc- tive evaluation methods are performed by ODOT staff members, third-party contractors, and consultants. This mixed use of nondestructive evaluation methods creates a significant issue for ODOT in storing and managing data. For example, some data are not collected with a geospatial component, and some data may be reduced to mile points and tabular results. Furthermore, some data are collected twice for different reasons because one division in ODOT may not know that another division in ODOT is doing a similar task. Despite the challenge, ODOT staff members mentioned that they gain a benefit in using nondestructive evaluation methods by not having to core as many locations. Lessons Learned ODOT uses a variety of technologies for highway inspection during construction and asset management. Lessons learned by ODOT in the use of these technologies include: • Creation of the engineering automation section—ODOT created the engineering automation section to manage the various emerging technologies that are continuing to increase in use annually. Additionally, ODOT uses steering groups from the engineering technologies services to gather information and conduct qualitative and quantitative analysis of a technology to determine its value to ODOT and whether the benefits outweigh the costs. By doing this, ODOT has determined the value in LiDAR, but it realized that IC was underperforming and discontinued its use. • Change management—ODOT believes it is important to gain buy-in from the staff and inspectors prior to the implementation of inspection technologies. Providing proof of the technology and showing that the implementation will make the staff’s and inspectors’ work more efficient tends to help gain that buy-in and allows those individuals to be more open- minded about changes in their daily tasks. ODOT commented that providing effective train- ing in the use of technologies helps overcome the perspectives of “this is how we always do it” and “why do we need to change?” Pennsylvania Department of Transportation The Pennsylvania Department of Transportation (PennDOT) has implemented various technologies over the past 10 years for highway infrastructure inspection during construction inspections and maintenance of assets. In 2013, PennDOT began using mobile devices for con- struction. Since that time, more technologies have been implemented, including geospatial,

Case Examples 91   remote sensing, and nondestructive evaluation methods. The following sections discuss the typi- cal technologies used by PennDOT for highway infrastructure inspection during construction inspections and maintenance of assets. Use of Technologies for Construction Inspection and Asset Management PennDOT recognized in the early 2000s that technologies would play an important part in inspectors’ daily tasks. One of PennDOT’s first initiatives was e-bidding, followed by a move toward the use of e-construction. As PennDOT implemented e-construction initiatives and digital project delivery, along with the advent of using mobile devices in the field, PennDOT staff members and inspectors came up with ideas for using mobile applications to replace the paper- based processes. As the initial applications were developed and implemented, the use of mobile devices showed that work could be accomplished digitally and more efficiently. PennDOT has a strong internal IT department that develops the applications and supports the personnel using the technologies, including inspectors and maintenance personnel. Using mobile applications and associated technologies allows PennDOT to collect data that can be easily shared rather than paper documents that are filed and unused. Contractors have supported PennDOT’s efforts to use more technologies in the field, as con- tractors realized that PennDOT is more efficient in inspection and payment when using technol- ogies. One particular technology that has been implemented with collaboration from industry is the use of e-ticketing for paving projects. On the basis of discussions within the industry on e-ticketing, PennDOT gained a better understanding of the technology and how it brings benefits to inspectors such as a safer environment for inspectors and easier-to-track materials. When considering inspection technologies, PennDOT evaluates the cost and return on invest- ment to determine the appropriate technologies for implementation. Furthermore, PennDOT investigates technologies from a user’s and contractor’s perspective. As mentioned by PennDOT staff members, it is important to PennDOT to determine the value of a technology, not only for PennDOT but also for its contractors and consultants. Once the value is determined and the technology is successfully pilot tested, PennDOT typically purchases and uses the technology on a larger scale. One of the main challenges that PennDOT has faced in using inspection technologies is the operational change typically required for using technologies. The PennDOT representatives noted that they often dealt with skeptics who were not willing to change their approaches to daily tasks. However, PennDOT has been successful in providing hands-on training for staff members and inspectors to use the technologies for inspections. Providing evidence that the technologies help with their work tends to bring the skeptics on board, and then they typically become advocates for using the technologies. Furthermore, PennDOT has trained experts that champion the use of the technologies and are available to help in the field if the staff is unable to use the technology correctly. Geospatial Technologies Application for Highway Inspection During Construction For construction inspections, PennDOT currently employs GPS, UAS, photogrammetry, and e-ticketing. As mentioned, PennDOT uses mobile devices in the field, and the tablets that are used include a GPS antenna to record the location of inspections and work progress for a project. Specifically, for guiderails and light pole installations, GPS coordinates are determined during inspections and are then fed into the maintenance GIS system to track the location of guiderail

92 Highway Infrastructure Inspection Practices for the Digital Age and light pole assets. The location of guiderails has been of particular importance as PennDOT was informed that some of its guiderails across the state were not manufactured in accordance with specifications. At first, PennDOT was not sure where these guiderails were located. With the use of GPS during installation, PennDOT was able to determine those specific locations and is mapping the remaining guiderails using GIS, showing the value in using both GPS and GIS. PennDOT has pushed for an increased use of UASs since 2019. For construction inspection purposes, UASs are used to monitor the contractor’s cut and fill tasks of a project to determine the amount of material removed or added. PennDOT noted that the use of UASs makes it easy to track the movement of materials and the progress of the work. PennDOT also uses photogram- metry with UASs to take aerial photos of a site to monitor the work progress. Before using UASs, PennDOT used to contract out to a third party to fly over sites, but with the implementation of UASs, it is easier for PennDOT to do the task itself. PennDOT has been piloting the use of e-ticketing with asphalt projects since 2017 and is one of the leading state DOTs in implementing e-ticketing. However, the use of e-ticketing was fast-tracked during the COVID-19 pandemic to eliminate the collection of paper tickets in an environment that did not allow for paper tickets to be passed among multiple people. PennDOT assembled a team of internal personnel, contractors, consultants, and suppliers to determine how to implement e-ticketing across the state, not only for asphalt paving but also for concrete paving projects. A specification was developed and approved, and all 11 districts within PennDOT are currently piloting the use of e-ticketing on asphalt and concrete paving projects as well as for aggregate placement. Application for Highway Infrastructure Inspection During Maintenance of Assets PennDOT uses GIS to map locations and provide information of assets, such as culverts and guiderails, across the state. GIS also helps the maintenance staff manage specific issues. For example, maintenance personnel take pictures of GIS-located culvert washouts annually, and if they see worsening conditions, proper decisions can be made for those particular assets. PennDOT also uses UASs for surveying existing road conditions to determine mill and fill maintenance needs. In addition, UASs are used for bridge inspections and for monitoring and tracking landslides, movement of slopes, and changes in rock faces and cliffs that may poten- tially affect highway assets. The PennDOT representative noted that UASs are used to fly over material sites such as salt sheds to determine the amount of material at the location, the amount that has been used, and whether the site needs more materials. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction Remote sensing technologies used by PennDOT for construction inspections include LiDAR, RFID, IC, remote sensors, infrared sensors, remote cameras, and barcodes and readers. LiDAR is currently used for surveying and monitoring work. The PennDOT representative noted that IC was used by PennDOT in the past with asphalt paving projects. However, IC is rarely used by PennDOT currently because of concerns about not achieving the specified compaction. As the technologies improve, PennDOT may revisit the use of IC in the future. Remote cameras are used on projects to collect time-lapse information on the progress of work, which helps PennDOT check the conditions of a project for inspection purposes as well as for claims filed by contractors. In addition, PennDOT employed the use of live cameras with audio at asphalt testing sites during the COVID-19 pandemic. Traditionally, PennDOT has

Case Examples 93   required an inspector to be on site during the entire paving test. During the pandemic, this was not allowed. Therefore, remote cameras were set up at the testing site, and paving contractors and inspectors were able to access the video feed and communicate live with the contractor. Inspectors could remotely monitor the asphalt sample testing without having to be on site. Finally, PennDOT currently uses barcodes, readers, and RFID technologies to provide necessary information about the particular materials to the inspector. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, PennDOT uses remote sensors, such as strain gauges and acceler- ometers, for evaluating highway infrastructure assets. Sensors are used in pavement structures to help inspectors observe how the structures flex and move over time. This information helps inspectors make timely decisions on the maintenance of pavement structures. In addition, accelerometers are used by PennDOT maintenance staff members on bridges when perform- ing maintenance work. Accelerometers provide information related to the stresses affecting the bridge that indicates when the bridge requires maintenance. Mobile Devices and Software Applications Application for Highway Inspection During Construction Mobile devices, including cell phones and tablets provided by PennDOT, are a primary tool used in the field by inspectors. The PennDOT representatives mentioned that many software applications for inspections have been developed over the past 5 years. Mobile devices have been key in PennDOT’s migration from paper-based delivery to digital delivery of construction and maintenance work. In addition to mobile devices, PennDOT uses 3D engineered models and AMG in construc- tion inspection. PennDOT noted that using 3D models in construction sites may provide vital information about a project for inspectors. Additionally, PennDOT currently uses AMG exten- sively because the technology has been in place for about 8 years. VR/AR is another technology that PennDOT is exploring for inspection purposes. The PennDOT representatives noted that PennDOT plans to purchase VR/AR devices and pilot them across the state for a variety of tasks, including construction inspection. This technology is tied to the development and improvement of 3D engineered models. An example of an area in which PennDOT hopes VR/AR can benefit is bridge inspections. The mobile VR/AR device can be used to show and overlay the bridge with planned work. The device, which also includes a video function, can be used to show relevant project personnel, the bridge’s condition, and associated potential solutions. Application for Highway Infrastructure Inspection During Maintenance of Assets The PennDOT representatives mentioned that the processes and procedures of using mobile devices and software applications for inspection of highway infrastructure assets are similar to those applied to construction inspection, as already discussed. Nondestructive Evaluation Methods Application for Highway Inspection During Construction PennDOT has used various nondestructive evaluation methods for construction inspec- tion. For example, PennDOT has used GPR, surface profiling, and dynamic test loading for

94 Highway Infrastructure Inspection Practices for the Digital Age piles. Similarly, ultrasonic testing, thermal integrity testing, and cross-hole sonic logging are used for inspection of drilled shafts. The PennDOT representatives noted that dynamic test loading is used on all installations of piles and that ultrasonic testing is used to check steel connections. GPR is used only for specific projects and types of work, such as checking rebar layouts on bridge decks. PennDOT has experienced limited success using GPR for underground conditions, especially in the state’s centuries-old cities. As PennDOT staff members men- tioned, “There is too much stuff underground in these cities and it is hard to trust what the GPR is showing.” However, as GPR improves, PennDOT plans to investigate its use more in the future. PennDOT is also exploring the use of combined nondestructive evaluation methods. For example, PennDOT is piloting the use of thermal integrity with cross-hole sonic logging of piers to better understand conditions within and around the piers. Pilot testing showed that this combined used of technologies was valuable, and PennDOT is proceeding with implementing it across the state. Application for Highway Infrastructure Inspection During Maintenance of Assets The PennDOT representatives noted that nondestructive evaluation methods are mostly used for highway construction inspection and are rarely used for inspection of highway infrastructure during maintenance of assets. Lessons Learned PennDOT uses a variety of technologies for inspection of highway infrastructure during construction and maintenance of assets. Lessons learned by PennDOT in the use of these tech- nologies include: • Leadership support—PennDOT realized early on that it is important to gain support from the department and state government to implement and use technologies in the field. PennDOT believes that buy-in from all levels of the department is key, and that having management’s support, as well as that of the state governor, is important for the use of technologies to help investigate, pilot, and implement a technology that may save time and money for inspection of new and existing highway infrastructure assets. • Providing proper training to the staff in the use of technologies—PennDOT noted that one of the challenges in using technologies to replace traditional methods is gaining buy-in from users and providing proper training to the staff and inspectors. PennDOT requires classroom training, but more importantly, PennDOT focuses on hands-on training in the field. Training also varies depending on the staff members being trained and the work that is to be performed with a specific technology. Additionally, PennDOT trains experts across the state who can assist users with specific technologies on a project site. South Dakota Department of Transportation The South Dakota Department of Transportation (SDDOT) has implemented various tech- nologies for the inspection of new and existing highway infrastructure assets. Currently, SDDOT has implemented all four technology areas studied in this synthesis: geospatial technologies, remote sensing and monitoring technologies, mobile devices and software applications, and nondestructive evaluation methods. The sections below summarize the SDDOT’s key findings from implementing these technologies.

Case Examples 95   Use of Technologies for Construction Inspection and Asset Management At SDDOT, the initial use of any technology requires an evaluation process to determine its value along with the associated costs of the technology. Typically, a work group is formed with in-house users and sometimes contractors to investigate the candidate technology. Work groups help SDDOT vet the process and select pilot projects to test the technology. The find- ings from the pilot projects are reported accordingly. The reported information helps SDDOT determine whether further use is warranted. If upper management agrees with implementing the technology, specifications are written or updated to create contract provisions that are included in the proposal documents for a project. If a technology needs to be implemented quickly, a change order may be used as long as SDDOT has buy-in from the contractor to use the technology. The SDDOT representatives mentioned that they typically use infor- mal benefit–cost analyses and return on investment assessments to evaluate technologies. However, costs are not necessarily quantified, but feedback from users in the department is considered. Geospatial Technologies Application for Highway Inspection During Construction For highway construction inspection, SDDOT has used GPS and RTSs for surveying prelimi- nary work, locating items of work, and recording quantities. The SDDOT representatives noted that the data generated from these technologies are manually entered into the construction management system for inspection purposes. One benefit of using geospatial technologies for highway construction inspection is the accuracy of the data collected. In addition, the project team can check data at any time during construction. The SDDOT representatives mentioned that using GPS and RTSs helps SDDOT offset the lack of inspection staff members and allows for better allocation of inspection resources. The main challenges of using geospatial technologies for highway construction inspection are keeping equipment and software updated and providing essential skill sets for inspectors so they can use these technologies. In addition, compatibility issues sometimes create complications, in that SDDOT uses specific software and file types that are not compatible with the programs used by contractors. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, GPS and GIS are crucial tools for locating transportation assets across the state. SDDOT’s asset inventories have GPS locations that are converted into a linear refer- encing system. Handheld GPS devices are used by inspectors, but recently SDDOT has been relying on iPads for GPS locations because those tablets provide accurate-enough information for locating transportation assets. The iPads also come equipped with an ArcGIS Collector appli- cation, which is a commercial application that SDDOT customized for its operations. Addition- ally, SDDOT is starting to use UASs with GPS to track and monitor asset conditions. UASs are especially helpful for assets that are difficult for inspectors to navigate, such as the underside of a bridge deck. The SDDOT representatives mentioned that using geospatial technologies has helped SDDOT develop comprehensive inventories of various assets, which helps the agency make better planning decisions. There are several challenges in using geospatial technologies for inspection of highway assets. For example, as in the case of construction inspection, keeping equipment and software up to date is challenging for SDDOT given the rapid technological changes. Other challenges include

96 Highway Infrastructure Inspection Practices for the Digital Age data management and accessibility and providing enough support for inspectors to use the mobile applications for asset inventory. Remote Sensing and Monitoring Technologies Application for Highway Inspection During Construction SDDOT’s use of LiDAR/3D laser scanning and IC has been limited, and SDDOT has also used remote cameras for highway construction inspection. SDDOT has only used IC on select proj- ects in the past couple of years. When using IC, SDDOT required the contractor to provide the IC data for analysis and review. The outcome of these projects is under evaluation, but SDDOT mentioned that setting up the IC correctly can be a challenge. However, SDDOT hopes that the use of IC will improve SDDOT’s densities for asphalt paving, especially late in the construction season when dealing with cold weather. The SDDOT representatives noted that consultants have employed LiDAR during construction, but SDDOT does not currently use it directly for inspections. Application for Highway Infrastructure Inspection During Maintenance of Assets For asset management, SDDOT uses remote sensors to monitor the movement of soils and track potential landslides that could affect transportation assets. SDDOT has also used remote- control cars with high-resolution cameras to perform culvert inspections. The remote-control cars have improved SDDOT’s asset inspections in that SDDOT can identify issues in places that were difficult to access in the past, such as underneath roadways. However, SDDOT has noted that the remote-control cars are not industrial grade and that they must be used properly and maintained on a regular basis. Mobile Devices and Software Applications Application for Highway Inspection During Construction SDDOT uses 3D models; AMG; tablets, laptops, and smartphones; and handheld data col- lectors for highway construction inspection. The SDDOT representatives noted that, although SDDOT has used 3D models for construction, 2D plans are still used by inspectors. However, SDDOT realizes that the next phase in design will involve digital contract documents that may eliminate the paper plans. As a result, SDDOT plans to use 3D models for all facets of construc- tion, including inspections, in the future. AMG is used at SDDOT with grading work, which has reduced staking requirements, espe- cially for wider grades. SDDOT adds a provision to contracts that requires contractors to use AMG and to provide the data to SDDOT. The contractor can build the project using the design files provided by SDDOT. Because of the observed improvement in accuracy from using AMG, SDDOT believes that it is a valuable tool for SDDOT’s operations. Finally, the use of smart- phones, tablets, and laptops has helped SDDOT effectively record quantities and improve communication among staff members and inspectors. Regarding handheld devices, Trimble products are used along with survey equipment to check variances in the field. Application for Highway Infrastructure Inspection During Maintenance of Assets The SDDOT representatives noted that only a limited number of mobile devices and software applications are used for inspection of highway infrastructure assets. For example, SDDOT previously used handheld devices to help with asset management, but those became outdated

Case Examples 97   and SDDOT switched to tablets. The switch required SDDOT to convert to different applica- tions from the customized software SDDOT had used on the handheld devices, which resulted in limited functionality in some areas of asset management. While the handheld devices had walked the inspector through the process, the tablets and the applications do not provide that level of detail. However, the tablets have now been successfully used for a few years, as their accuracy is better than the previously used handheld devices. The tablets also have GPS, which allows SDDOT to locate assets and note their condition. The main challenge in using tablets for asset management is cellular coverage issues. The SDDOT representatives noted that, although cellular coverage has improved in recent years, some areas with more hills (e.g., Black Hills) still lack coverage. Nondestructive Evaluation Methods Application for Highway Inspection During Construction SDDOT has implemented several nondestructive evaluation methods for construction inspection. For example, GPR has been used to check reinforcing steel placement in concrete pavements and structures. Surface profile measuring is used on a regular basis for new asphalt and concrete pavements. Ultrasonic testing is employed to check welds. Falling weight deflec- tometers are used to inspect roadway base stability. Cross-hole sonic logging is used for all drilled-shaft construction. Nuclear density gauges are mostly used for soils, but they have also been used for low slump concrete on bridge deck overlays and for asphalt pavements. The SDDOT representatives noted that using nondestructive evaluation methods provides SDDOT with the ability to check contract compliance of materials more accurately without having to damage other work. However, when issues are discovered, corrective actions may require removal and replacement of the work, which initiates disincentives in the contract that are applied to the contractor. Application for Highway Infrastructure Inspection During Maintenance of Assets The SDDOT representatives noted that nondestructive evaluation methods are rarely used for inspection of highway infrastructure during maintenance of assets. SDDOT has tested GPR for inspection of highway assets but did not have much success. For example, when using GPR, SDDOT was unable to reliably detect voids around culverts. SDDOT did acknowledge that the setup may not have been ideal and future use may be considered if accuracy is improved. Lessons Learned SDDOT uses a variety of technologies for inspection of new and existing highway infrastruc- ture assets. Lessons learned by SDDOT in the use of these technologies include: • Proving the accuracy of the technology in use—SDDOT notes that geospatial tools provide accurate measurements for surveying, but they may not be as accurate as traditional means, especially for verifying slopes. • Keeping equipment and software up to date—SDDOT stated that having the proper equip- ment with the current firmware, as well as current versions of software applications, is essen- tial for eliminating mistakes. SDDOT believes that keeping equipment and software updated is also important for managing data so that data can be transferred and shared seamlessly with others in the department. • Working with contractors—SDDOT employs working groups to review and test tech- nologies to ensure the cost-effective and efficient use of inspection technologies. The

98 Highway Infrastructure Inspection Practices for the Digital Age working groups typically include third-party contractors and consultants. In fact, SDDOT has gained several innovative ideas from the working groups that are currently being implemented. Summary This chapter presents key findings on various technologies used by eight DOTs to inspect highway infrastructure during construction and maintenance of assets. The DOTs included in this chapter have a wide variety of experiences in using inspection technologies. Almost all of these eight state DOTs (Florida, Illinois, Iowa, Minnesota, New York, Oregon, Pennsylvania, and South Dakota) have more than 10 years of experience in using at least two of the following four technology areas for highway inspection: (1) geospatial technologies, (2) remote sensing and monitoring technologies, (3) mobile devices and software applications, and (4) nondestruc- tive evaluation methods. The following are discussed in detail: general findings on the use of technologies for inspection of highway infrastructure, the main applications of each of the four technology areas during construction and maintenance of assets, and key lessons learned from using inspection technologies. Several state DOTs in the case examples (Illinois, Minnesota, New York, Oregon, and Pennsylvania) realized the benefits of providing proper training to their staff and inspectors for the implementation of inspection technologies. The Florida, Iowa, New York, and South Dakota DOTs also observed that keeping equipment and software up to date and maintaining the technology and associated equipment are important for eliminating mis- takes and managing data when using inspection technologies for highway infrastructure during construction and maintenance of assets. The New York and South Dakota DOTs observed the benefits of working with contractors, consultants, and researchers to gain innovative ideas and better understand the cost-effective and efficient use of inspection technologies. Finally, the Illinois, Iowa, Minnesota, Oregon, and Pennsylvania DOTs noted the importance of gaining leadership support during the implementation of inspection technologies for highway infra- structure during construction and maintenance of assets.

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Historically, state departments of transportation (DOTs) have employed on-site workforces to execute infrastructure inspection using traditional inspection methods.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 582: Highway Infrastructure Inspection Practices for the Digital Age documents the various technologies - such as unmanned aircraft systems (UASs), embedded and remote sensors, intelligent machines, mobile devices, and new software applications - used by DOTs to inspect highway infrastructure during construction and maintenance of assets.

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