Transportation organizations are continually faced with the need to maintain, access, and share information related to multimodal transportation systems. Geographic Information Systems for Transportation (GIS-T) are increasingly used to capture, assemble and disseminate much of this information. The results of the work performed under NCHRP Project 20-27(2), "Development of Systems and Application Architectures for Geographic Information Systems in Transportation," confirmed the assertion that the vast majority of transportation data are referenced to location. Moreover, the level to which transportation business data can be integrated is directly dependent upon a robust model for location referencing. The timeliness and significance of the location referencing system (LRS) data model developed in NCHRP Project 20-27(2) is evidenced by the application of the model in several state DOTs. Further, there has been continuing interest in a number of transportation organizations to extend the model or re-evaluate their approaches to location referencing on an agency-wide basis.

Further research is necessary to develop a comprehensive LRS data model that encompasses multimodal, multi-dimensional locations of stationary objects as well as moving vehicles. Numerous efforts have shown that LRS data models vary significantly across transportation organizations and often within organizations as well (e.g., legacy data within a DOT may be based upon different LRSs). This has resulted in ineffective systems and even abandoned efforts as organizations attempt to implement improved transportation information systems and advanced GIS-T technology. Research is needed to provide detailed insights, functional requirements, models, and guidelines so that transportation organizations can easily incorporate the results into their operational systems. The integration of location referencing systems with linear referencing systems is necessary for effective facilities management and real-time monitoring applications.

The objectives of this research were to (1) establish consensus based functional requirements for a multi-dimensional LRS data model for multimodal transportation systems, (2) develop an improved LRS data model, and (3) develop guidelines to implement an improved LRS data model in transportation organizations. The LRS data model should handle the functional requirements of multimodal transportation systems, be stable and manageable over time, cost-effective to implement and maintain, and extensible to future technological innovations including data access and visualization advancements.

To accomplish the above objectives, the following tasks were conducted: (1) Review the efforts of transportation organizations to establish and maintain location referencing systems and to establish LRS data models to relate relevant factors. Identify important factors, major problems, emerging issues, and the experiences relative to organizational re-engineering and the implementation of new technologies. Contact key professionals and agencies directly, as appropriate, to gather relevant facts. The contractor will be expected to document the findings in a working paper that will be incorporated in the interim report (Task 4) and used to provide background for the workshop (Task 5) participants. (2) Develop a plan for a workshop that will aim to establish a consensus on the functional requirements for an improved LRS data model. The contractor should develop a workshop program that includes background presentations by noted professionals, breakout sessions that will allow detailed discussions of LRS data models and their functional requirements, and plenary sessions that will allow the entire group to assess needs and priorities associated with LRS implementation. The workshop program should use structured techniques to assure a systematic review of LRS data model capabilities and shortcomings across the myriad of transportation organization functions. This systematic review should be geared to address the functional requirements of LRS in the context of various information management strategies, agency structures, and technologies (e.g., GIS, data warehousing). It is anticipated that a two-and-a-half day workshop will be scheduled. The plan should describe the materials to be used, the means that will be employed to capture the feedback received at the workshop, and the outline for the workshop proceedings. (3) Select 10-15 transportation organizations that have undertaken efforts to implement a new LRS to participate in the workshop. Identify the one or more individuals to represent each agency. It is expected that the workshop participants will be limited to the invited transportation organization personnel, the panel, members of the research team, and a small number of other "experts" who could contribute to the discussions. (4) Submit an interim report that (a) summarizes the current practices, (b) describes the experiences of transportation agencies in implementing LRS data models, (c) indicates the technological issues that must be faced, and (d) assesses the organizational and political factors that must be addressed. The interim report should also describe the planned program for the workshop, identify the recommended participants, and provide details on the plans for conducting the workshop. (5) Conduct the workshop in accordance with the plan approved by the project panel. Provide the necessary logistics support for documenting the discussions and conclusions reached during the workshop. It is expected that the workshop will lead to consensus on a set of functional requirements for LRS data models. The contractor will be expected to prepare workshop proceedings to document the functional requirements defined and summarize the considerations that led to their development. (6) Refine the functional requirements for the LRS data model, after the workshop, through additional analyses, follow-ups with experts, and/or assessments of institutional (e.g., downsizing, re-engineering) and technological (e.g., GPS, soft-copy photogrammetry, web browsers) factors. The contractor will be expected to describe and justify these refinements in a working paper for the panel within three months of the workshop. (7) Translate the functional requirements into an improved LRS data model. Assess the revised model against the location referencing needs identified during the workshop and compare it to the capabilities of existing models. Determine where the LRS data models need further modification to fully address the functional requirements. Proposers are expected to describe in their proposals how this task will be undertaken. (8) Formulate an improved LRS data model that fully addresses the functional requirements. Assess opportunities and constraints for implementation providing illustrations of the experiences of transportation agencies. Formulate guidelines for the implementation of an improved LRS data model that will overcome organizational, institutional, and technological constraints. (9) Present the revised model to a forum of users to gauge acceptance from a broader range of perspectives. Implement a process to capture further feedback on the revised model after the presentation for a three-month period. Summarize the feedback and make revisions to the model as approved by the panel. (10) Prepare a final report that documents the research and findings. An executive summary geared to management should be included.

Status: The project has been completed.

Product Availability: The report has been published as NCHRP Report 460.