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1Executive Summary Introduction Most highway renewal projects require the establishment of an underground utility inventory before detailed design. The processes used to establish a complete understanding (positional and functional) of the underground utilities can be costly and time-consuming. Often a project area is composed of one or more sections of previous renewal projects where the utility inventory was established and well documented. The number of underground utility changes since the last construction project may be few; however, processes to track these changes have not been estab- lished. Some of the records that document the underground utility changes may be insufficient, incorrect, or difficult to obtain. Because there is no mechanism in place to track changes to department of transportation (DOT) rights-of-way, the entire project area is resurveyed, which requires locating 100% of existing utilities when only a small percentage of these have undergone change. SHRP 2 Renewal Project R01A developed several strategies, processes, and systems to acquire, store, use, and maintain 3-D utility location data from prior projects, which will help pre- vent repeated re-inventory of utility features on new renewal projects. The SHRP 2 R01A projectâs resulting products have the potential to help avoid problems typically encountered from delays that unknown utilities may cause, as well as to avoid damage to utilities from dig ins and service interruptions. The proposed solution was crafted for use during planning, design, and construc- tion. The solution has potential value as a dynamic, day-to-day process for maintaining an accu- rate database of all such features for the management of assets (both DOT and permitted encroachments) within highway rights-of-way and thus may have even greater usefulness for DOTs and transportation users. The SHRP 2 R01A project was executed in three phases. Phase 1 consisted of a literature search of the best practices worldwide for cataloging and maintaining utility infrastructure. The Phase 1 research identified a strategy to create a solution that would serve the needs of state DOTs on future renewal projects. A proof-of-concept model was developed to test the viability of the Phase 1 strategy and the capability of the system to integrate with DOT project design. This Phase 1 testing included a verification of the systemâs suitability for maintaining the utility record in the DOT right-of-way during design and construction, as well as for subsequent renewal projects. The Phase 2 work tested the processes and systems for scalability, relevance to the DOT design process, and validity of the results for implementation in the Phase 3 pilot. Phase 3 incorporated all underground utility features from a project located in Northern Virginia at the intersection of Route 29 and Gallows Road. The Phase 3 pilot project used the technology from the Phase 2 proof of concept but included a much larger set of data, simulating underground utilities on a typical DOT project. The pilot system and work processes developed in Phase 3 provided an opportunity to test the basic 3-D utility model for completeness. The 3-D model was used in several workflows, proving the capability of the system to perform basic
2highway-design work and demonstrating the suitability of the overall solution for future DOT renewal projects. The SHRP 2 R01A pilot project at Route 29 and Gallows Road established a number of admin- istrative and technological practices required to acquire, preserve, and maintain the utility record for all future projects. The pilot system demonstrated the use of many types of data typically used to define the true 3-D nature of the utility features. One of the strengths of the pilot system was the application of quality levels as defined by the ASCE 38 standard (Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data, ASCE/CI 38-02). The system transforms the ASCE 38 classified underground utility features into an easily understandable graphic. The graphic is created through the use of symbology discretely rendering each utility featureâs quality level. All utility features with quality levels A through D are loaded into the system, and each classification level is easily distinguished by color, line size, or a combination of symbology and color. Phase 1 Findings The Phase 1 literature research resulted in a number of findings that formed the basis of the development of the Phase 2 proof of concept: ⢠The reviewed projects contained an integrated view of all utilities in the right-of-way. ⢠To manage change, several of the organizations had a systematic means of identifying and recording change. ⢠The permitting agencies that issue permits within the DOT right-of-way should provide a systematic and direct means of defining areas where the underground utilities have changed. ⢠All of the systems were based on a centrally processed data store. While many DOTs operate by region or division, the system design should offer the opportunity to consolidate the data stored for underground utilities into a single statewide system. ⢠Multiple organizations accessed the data for a variety of purposes. This finding suggested that the system proposed should allow secured and controlled access to a variety of users. The system should also deliver the data in a form that can be accessed by a variety of viewing and editing tools. ⢠Almost without exception, the literature pointed to process reengineering as a key element of the various implementations. Process reengineering was one of the main change catalysts that provided significant efficiency improvement and accounted for much of the cost savings. ⢠The implementation of a data quality standard was found in only one instance. However, because several of the research papers provided many strong arguments for implementing a data quality standard, it is included as one of the more significant findings. ⢠One area that needed process improvement was the practice of recording as-built under- ground utility locations postconstruction. The traditional practice of marking up a set of design plans (as-built locations by exception) could lead to inaccurate utility data. Sampling processes that generate actual location and utility definition are better suited to ensuring that the actual locations of the underground utilities are recorded and known. ⢠Finally, the Virginia DOT implemented the use of RFID markers for permanent marking as a best practice. This best practice has proved its value: damage to several utilities during con- struction was avoided. System Overview Using the results of the literature search, the proof-of-concept system was crafted to address a number of the findings and included three logical components: (1) a content management system; (2) a 3-D utility data storage system; and (3) a client component for viewing and editing the underground utilities.
3Content Management System The content management system allows the collection of utility data in many different formats and serves multiple purposes. The system ⢠Provides a staging platform for collection of utility data and any associated records for pro- cessing into the 3-D utility model; ⢠Allows the classification of underground utility source data to ASCE 38 quality levels; and ⢠Will allow for direct viewing of the base files in 2-D space. The content management system is a logical collection and notification point for all changes (permits) to the project area during design and construction and subsequent to project completion. 3-D Utility Data Storage System The 3-D utility data storage system was built on a standard relational database product, Oracle with Oracle Spatial as a spatial overlay environment. Any number of relational database products could have been used for the pilot (e.g., IBM DB2, IBM Informix, Microsoft SQL Server), but Oracle Spatial was chosen because it is the product most commonly found in many state DOT computing environments. The decision to store the 3-D utility data in a spatial environment was made to satisfy scalability concerns. The utility data being stored is 3-D point, line, and polygon data modeled using the federal Spatial Data Standards for Facilities, Infrastructure, and Environ- ment database (SDSFIE 3.0). The SDSFIE data model was modified and extended to provide a richer set of definitions for underground utility features and to allow 3-D spatial features storage. Additionally, SDSFIE was extended to store and supply a number of additional features not com- monly found in SDSFIE, features that can be processed to manage change and provide additional base map information common to highway design. The 3-D utility data storage system is used to store and maintain the utility system of record for DOTs. It is envisioned that all underground utility design, underground utility as-built con- ditions, and permits will be stored and maintained in the 3-D storage system, providing the utility record for future renewal projects. During the pilot project, several demonstrations were performed to show utility design using the system. Client System The third component of the system, the client tools section, is represented by a variety of engi- neering tools commonly used by DOT designers. Bentley Systemâs MicroStation, InRoads, Bentley Map, and several web-based viewing tools were used to demonstrate the interoperability of the various CAD and spatial products. Because the demonstration was limited in time, addi- tional non-Bentley viewing and editing tools were not demonstrated for their ability to view and edit the 3-D utility features stored in the 3-D utility data storage system. Conclusions The practice of re-inventorying utilities for future DOT projects can be avoided by implement- ing a solution described in detail in this report. The results of this project demonstrate that 3-D utility data can be collected, stored, and maintained in a single statewide system for direct use in future highway renewal projects. Each state DOT will directly benefit by including all the utility underground features in the system. Adopting, adapting, and using the 3-D model (see Appendix A and Appendix B) in multi ple states will provide opportunities for DOTs to transparently share data where projects span state boundaries.
4Instituting a change control process over project sites is a key R01A project recommendation for avoiding re-inventory of entire underground utility systems. In particular, a permitting pro- cess will serve as a primary way to avoid re-inventory when underground utility data are changed and will ensure that the underground utility system of record can be relied on for use in future highway renewal projects. The system was built on technology that allows the generation of fully defined 3-D CAD features from single point, line, and polygon spatial definitions. Without this technology, it would be difficult to store all the utility features under an entire stateâs highway system and scale it for performance. While this technology is not new, this is the first time this technology has been used to manage the scalability concerns regarding storing large vector-based CAD models to create a 3-D underground utility system of record. This capability is available in other vendorsâ CAD systems, but it is not necessarily being used for the purposes demonstrated in this research project. Successful implementation of the techniques, processes, and recommendations described in this report using other CAD technology providers can be achieved by using developers and business partners intimately familiar with the spatial storage environments supported by the different CAD vendorsâ products.
