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3 INTRODUCTION State transportation agencies are under increasing pressure to do more with less. From Maine to Hawaii, many agencies are experiencing significant staff reductions. To maintain their cur- rent level of service, these agencies are considering investing more in advanced geospatial data tools and technologies. The good news is that highway administrators, engineers, surveyors, planners, designers, and contractors have access to an increasing variety of powerful geospatial data tools, technologies, and information. The challenge is that making full use of these new methodologies often requires significant organizational change. Today, significant variability exists in the level of geospatial information provided with project results and the associated allocation of risk based on the procedures used. Some of these technologies do not have adopted standards or guidelines. For example, few well-defined standards exist for the use of Light Detection and Ranging (LIDAR) systems, and in many cases incorrect techniques are employed. There is also substantial variability regarding the scope of and data submittal require- ments for geospatial information, the program of geospatial- related quality control and assurance during construction, and the contract provisions related to design and construction posi- tioning requirements. Simultaneously, the core information technology platforms upon which the transportation agencies operate are transition- ing from two-dimensional (2D) to three-dimensional (3D), significantly disrupting the status quo. Design is moving from paper-based 2D plan and profile to digital 3D models; survey is beginning to use static and kinematic LIDAR; and contrac- tors are adopting the use of Automated Machine Guidance (AMG). In addition, the pace of change is accelerating. As a result, the cost-effective use and management of geospatial information and emerging positioning/measurement technolo- gies will be beneficial to successful operation. Transportation agencies embracing this rapid change, rather than seeing it as a threat, will be able to realize higher efficiencies because these technologies and information will enable divisions to work together and streamline their operations. There are limitations to each of these tools and technolo- gies; one size does not fit all. Many individual transportation agencies have performed research studies and pilot projects to understand the potential of these tools and technologies, as well as their limitations and risks. Case studies have been developed by these agencies to illustrate and address the issues cited earlier. Some of these agencies have established guidelines that describe which tools can be used to meet spe- cific positioning requirements, including establishing sur- vey control and coordinate systems for automated machine control and guidance, using LIDAR systems for the devel- opment of 3D data models, determining how to use satellite imagery effectively, using two-way data exchange formats between computer-aided design (CAD) and Geographical Information System (GIS), and developing tools for web- based data exchange and editing. This information, however, is fragmented, scattered, and unevaluated at this time. Often, the information is transferred from person to person only at national conferences and meet- ings. As a result, transportation agencies are not benefiting from these costly research studies and pilot projects, and are unable to give proper consideration to recommended prac- tices that meet their positioning requirements and manage their associated risk. GEOSPATIALâINFRASTRUCTURE LIFE CYCLE Geospatial technologies and information provide core support across most transportation operations. These technologies can help integrate divisions by providing a framework to link and share each divisionâs data into a unified geospatial transporta- tion model. For example, an integrated model for a bridge can be queried by various divisions within a transportation agency, including structural engineers, geotechnical engineers, traffic engineers, and maintenance crews. As each organization docu- ments an inspection or updates the bridge database in this cen- tral model, the other divisions can be informed immediately of these efforts and have that information to assist them in their future tasks. These geospatial technologies are valuable at all phases of infrastructure projects, from new construction to routine main- tenance. Figure 1 illustrates the concept of an infrastructure life cycle, where several cycles of decision making are aided by geospatial technologies during the acquisition, modeling, analysis, and application phases. All projects, including maintenance, result in some form of data being collected, whether it is documented using a chapter one INTRODUCTION AND SCOPE
4 technology or through human observations. With a central- ized, geospatial information model that is updated by all departments, all historical data can be leveraged at any phase of a project. In many cases, these data will still be usable. In other cases, historical data can be instrumental in the planning of any additional data collection. The acquired data are then converted into models to enable the data to be analyzed in design and planning pro- cesses. When construction or maintenance is required, these models can be used to support the project. The geospatial life cycle should not end at the comple- tion of a project. It should continue as data are collected before the start of a project and through all phases of main- tenance and construction as part of the infrastructure life cycle (Singh 2008). Updating this geospatial information database with rou- tinely collected maintenance and other data enables analyses to be performed in context. Field crews can use that informa- tion to plan their schedules to perform all necessary work in an area, minimizing losses in time and money for travel. Unfortunately, such a model rarely exists and requires substantial discipline to create. However, the sooner an orga- nization starts to develop a model, the sooner it will have those resources available. Continual implementation of this life cycle will enable many of these benefits to be realized. TECHNOLOGY BACKGROUND The purpose of this report is to examine the state of the practice relating to the gathering, analyzing, storing, and use of geo- spatial data in transportation agencies. These are topics that are coming to the forefront of the workflows of transportation agencies with the advent of geospatial gathering tools and tech- niques, such as Global Navigation Satellite System (GNSS), LIDAR, 3D image reconstruction, and AMG. With these new collection tools, data are collected faster and in greater quanti- ties than ever before. Thus, it is essential that these tools and data be integrated and used effectively for a variety of appli- cations to minimize duplicate or unnecessary data collection and to enable the same data to be queried across disciplines, departments, and projects. GIS platforms enable integrated, geospatial data manage- ment by combining spatial information with attributes. This versatility enables numerous informational tools to be cre- ated and visualized. GIS can help to show the public some of the magnitude of infrastructure projects by way of maps that tell stories. Previously, the cost associated with creating these types of maps was not warranted, so the work went undone. In addition to providing an efficient way to inform the public FIGURE 1 Geospatial tools applied across various phases of infrastructure life cycle.
5 about these projects, GIS can provide decision makers more metrics with which to make important decisions. Furthermore, these tools can help expedite project design and quality man- agement to ensure that completed projects more closely match final designs, ultimately reducing costs and improving quality. Linear referencing systems (LRS) are used by some trans- portation agencies, many of which are integrated into a GIS. These systems define a known starting point and reference locations of objects at a linear distance from that point. This is an alternative to the geographic coordinates location method. Common uses of LRS are asset management and emergency response, where crews may not have a global positioning system (GPS) unit. GNSS technology has become an indispensable tool for the completion of transportation projects ranging from survey (at the millimeter to centimeter level) to inexpensive hand-held (decimeter to meter level) grades. Continuously Operating Ref- erence Stations (CORS 2012) are now located throughout the United States and enable improved data accuracy. With hand- held units returning data well suited for asset management and accuracy levels in consumer grade systems increasing, a com- mon trend toward GPS integration across the organization has been noted by transportation officials. LIDAR data can be obtained from terrestrial, mobile, and airborne platforms, depending on project needs (typically resolution, accuracy, and extents) and budget. This technol- ogy enables the quick collection of high-resolution (millimeter to decimeter level) spatial data. With new mobile and airborne LIDAR systems using highly accurate GNSS and inertial mea- surement unit (IMU) systems, the spatial data are completely geo-referenced. Initial cost, processing time, and specialized training and software are the main drawbacks of this technol- ogy. However, as this technology becomes mainstream, the cost becomes more manageable for government agencies. The benefits created are quickly being shown to outweigh associated costs, especially when compared with traditional techniques. Further, new processing technologies are emerg- ing to automate some of these processes, enabling more peo- ple to make use of the data. Aerial photography is a useful tool for the visualization of current, past, and proposed projects. Photogrammetry uses stereo pairs of imagery to enable measurements with a data set con- taining x, y, and z coordinates. Because photogrammetry has been used for decades, it is well understood and can serve as a stand-alone product, a complementary aid, or a quality control measure for emerging LIDAR technology. As photographic resolution and quality have improved in the digital era, new advances of photogrammetric algorithms have enabled dense 3D point clouds to be reconstructed from a series of 2D images. Despite these advances, it is important to realize that all of these technologies are tools and the end user selects the most appropriate combination of each for use in particular jobs. Although some traditional surveying tools can be replaced by more efficient means in some cases, many traditional tools are still needed. The traditional tools provide vital quality control as new technologies are developing. In addition, tradi- tional surveying tools are tried, true, reliable, and understood well by people in the geospatial industry. Additional technologies that will be addressed in this report include ground penetrating radar (GPR) and its use in roadway roughness analysis, video logging for traffic analyses and project progression, and the integration of tablets and smartphones into transportation workflows. This report can serve as a reference source for understand- ing these emerging technologies. Creating a solid framework of these current geospatial data, tools, and technologies will serve as a foundation for the transition from 2D to 3D. ORGANIZATION AND HUMAN FACTORS In theory, a technology may be able to provide valuable infor- mation and dramatically reduce costs on a wide variety of projects; however, if it cannot be effectively implemented by an organization its value will not be realized. In addition, new technologies often require people to adapt to new workflows. Implementation of a new technology requires a transporta- tion agency to examine all potential costs (e.g., equipment purchase, accessories, training, and maintenance) and ben- efits (e.g., ability of data to be used by multiple departments). Internally, transportation agencies are choosing what level of geospatial technology usage produces the optimal benefit-to- cost ratio for their organization. The following represents four possible levels of involvement with a new technology: 1. Transportation agency chooses to invest in a particu- lar technology and acquire software, hardware, and training. 2. Transportation agency develops a working knowl- edge of the technology and is able to implement basic processing and data manipulation. However, the bulk of the acquisition and processing is completed by a consultant. 3. Transportation agency can use derivative products of the technology provided by a consultant but has limited knowledge of the technology. 4. Transportation agency decides not to use the technol- ogy (e.g., the technology has not been proven to pro- vide acceptable results, the technology has a lower benefit-to-cost ratio compared with other technologies, and so forth). SCOPE Rather than each transportation agency allocating resources to perform its own research studies and pilot projects to inves- tigate how best to adopt and manage advanced geospatial
6 technologies, this study documents and summarizes the current state of the practice throughout the United States as of 2012, including emerging standards and guidelines. In addition, this study identifies gaps in the research needed to achieve the desired level of systems integration and assist transportation agencies in developing a systematic approach to adopting these technologies into standard oper- ating procedure. The key purposes of this study are to: 1. Document and summarize the current state of the prac- tice related to advanced geospatial data tools, technolo- gies, and information for highway projects, including procedures and proposed standards of practice that can be used to attain the information objectives when using these advanced geospatial technologies. 2. Identify how, when, and why these tools are used in combination to attain stated objectives. 3. Identify potential research needs, such as develop- ment of effective tools for assessment and manage- ment of risk. 4. Document practices and applications using advanced geospatial data tools, technologies, and information, and make the results available to the entire transportation community. 5. Produce a report that will help transportation agencies develop effective procedures in support of planning, design, and maintenance and operations functions. This report serves as a synopsis of the recent developments related to advanced geospatial data, tools, and technologies. These include GNSS, automated machine control, LIDAR, photogrammetry, 3D visualization, robotic and manual total stations, leveling, satellite remote sensing, GIS, GPR, video logging, and tablets and smartphones. This report also shows the current usage trends for these technologies within trans- portation agencies. The introduction of a new technology into any organiza- tion carries a certain amount of risk. This report intends to pro- vide the most up-to-date information on the best practices and lessons learned to help minimize that risk. However, it is not likely that all risk can be eliminated. Thus, it is important to recognize and plan for short-term setbacks during the adoption phase. These should be expected and are the reason it is impor- tant to document both successes and failures. In the end, it is a matter of managing expectations and being realistic about managing change in a complex organization, such as a trans- portation agency. Some key challenges faced by the transportation agencies in adopting these technologies are as follows: 1. Large data sets are the result of gathering geospatial data with high resolution. In some cases, these can be on the magnitude of millions or even billions of points. Storing and processing these data in a cost-effective manner requires analysis and planning. 2. New technologies consist of a wide variety of mechan- ical, electrical, and computer components. Technical expertise and special training often are required to pro- cess and use the data efficiently. 3. These emerging technologies are changing rapidly, making it difficult for any organization to stay cur- rent. Different techniques using these technologies emerge quickly, sometimes rendering ânewâ equip- ment obsolete. 4. New workflows and procedures are being developed without standardization or well-defined best practices. Transportation agencies are faced with creating these frameworks as advanced geospatial data, tools, and technologies are integrated into their workflows. 5. Significant resistance to change can occur when devel- oping new geospatial workflows. Justifying the dedica- tion of resources toward these efforts can prove difficult for transportation agencies. Some key beneficial opportunities anticipated by the trans- portation agencies with the use of advanced geospatial tech- nologies can include: 1. Transportation agencies are being asked to do more with less. Geospatial technologies offer transporta- tion agencies the ability to increase productivity to at least maintain, if not improve, their current level of service. 2. New technologies can produce significant safety ben- efits for field personnel and the traveling public. 3. Significant cost savings can be realized by using these new technologies and maximizing the return on invest- ment through the sharing of data between divisions. 4. Up-to-date geospatial data can lead to more informed decision making and better use of scarce resources. This can be especially important for rapid response to emergency situations. 5. The adoption of nationally recognized standards and methods offers transportation agencies the ability to share information across state lines and leverage investments made by other agencies. 6. The development of a reliable and actionable trans- portation data model can establish the transportation agency as a go-to source for accurate information by other state agencies and the legislature. Ryerson and Aronoff (2010) outline the âGeoEconomy,â an emerging concept of an economy driven by and depen- dent upon geospatial information. This forward-thinking book presents concepts that link geography-based data with future economic trends. Tying these two concepts together, the authors offer insights related to gaining the âGeo-advantage.â This resource is not tailored to one
7 audience; rather, it can be implemented by individuals and governmental organizations alike. STUDY APPROACH: METHODS OF INFORMATION GATHERING AND DELIVERY Questionnaires A geospatial data technologies questionnaire (chapter two) was developed and distributed to relevant geospatial con- tacts from state and federal transportation agencies obtained through a questionnaire for project NCHRP 15-44, state TRB representatives, as well as AASHTO standing committee members from GIS-T (GIS for Transportation), Research, Planning, Design, and Asset Management. Because geo spatial technology is implemented by a large range of personnel across the departments of transportation (DOTs), the question- naire was sent to multiple lists, rather than just the GIS-T list. However, the goal was to obtain at least an 80% response rate from the GIS-T list. A total of 42 of the 52 GIS-T representa- tives completed the questionnaire. Ninety-seven responses were obtained from 48 of the 50 state DOTs, plus two from Puerto Rico, one from the Dis- trict of Columbia, and one response from Alberta, Canada. Results of this questionnaire aided in the analysis of the current usage of advanced geospatial technologies within individual DOTs. Such analysis helped identify which DOTs have experience and expertise with key geospatial technolo- gies. The questionnaire also determined which states have integrated geospatial standards and specifications into their workflows, particularly as they relate to performance-based accuracy requirements. Another key aspect to this questionnaire was to determine where DOTs publish research reports related to geospatial tech- nologies and what topics require additional research. Addition- ally, questions were asked to determine which DOTs typically published these findings so that the entire transportation community can benefit from them. A second questionnaire targeted private sector service providers, including geospatial tools and software vendors, contractors, and consultants. Providers to be interviewed were selected by the following criteria: (1) providers who work frequently with DOTs, (2) providers who are active in disseminating experiences at national and international conferences, and (3) geographical distribution of selected providers across the country. This was included to provide an external, third-party perspective of current transporta- tion agency data, tools, and technological products as viewed by industry service providers. Despite the small sample size (13 of 16 contacted) compared with that of the DOT respondents, the service provider questionnaire helps to draw some common inferences and determine themes and trends in current geospatial technology usage. A summary of the results regarding current practice is presented in chapter three. Literature Review of Individual States, Foreign, and Private Practices An overview of literature related to geospatial data tools, technologies, and information as they apply to transporta- tion projects was compiled and summarized. This included a review of common sources, including magazines, confer- ence proceedings, journals, reports, and online resources [e.g., the Transportation Research Information Database provided by TRB, state agency annual reports on Highway Engineering Exchange Program (HEEP)]. Several contacts in various agencies, including state DOTs, ASCE, American Society of Photogrammetry and Remote Sensing (ASPRS), American Congress on Surveying and Mapping (ACSM), National Geodetic Survey (NGS), TRB (particularly commit- tee AFB80), and ASTM, provided input on both needs and available knowledge on advanced geospatial topics. The pro- cedures and results for this literature search are described in more detail in chapters four through seven. GIS Research Database Accompanying this report is a searchable GIS (Figure 2), Google Earth (Figure 3), and spreadsheet database contain- ing layers specific to current and past geospatial research, specific state-of-the-practice geospatial guidelines and speci- fications, and concurrent projects using prototypical geo- spatial technology. This searchable matrix also includes relevant agencies that publish reports, journal papers, conference papers, and white papers related to geospatial technology, with hyper- links to sources of information such as DOT research office web pages where reports are published. This provides a solid background for transportation agencies to study current geospatial technologies. The list of resources for this synthesis was compiled by the study team into an MS Excel spreadsheet. This spreadsheet serves as the common link to the GIS database provided in Appendix C. In addition to the study title and associated state or organization, fields such as issuing and performing organi- zations, key words and concepts, hosting address, and main technology type are represented. These fields were added for enhanced querying, filtering, and sorting capabilities. Potential expansion to this database identified by the study team could include continued work with transpor- tation agencies and private organizations for the inclusion of relevant research, an author field, and development of a web-based, graphical user interface for simple user naviga- tion without the need for GIS software.
8 Legend states StaticLIDAR <Null> Not Using Not Sure Investigating Researching Implementing SOP FIGURE 2 Example of GIS database showing static LIDAR usage by state DOTs. FIGURE 3 Example of Google Earth database showing static LIDAR usage by transportation agencies.
