3. STUDY METHODOLOGY AND INFORMATION SOURCES USED

3.1 STUDY METHODOLOGY

            The objective of the state-of-the practice review is to gain an understanding of which ITS project is collecting what data elements, and to identify which data are archived. If data are archived, then ORNL identified how these data are archived, for what purposes these archived data are being used, and by whom. If data are not archived, then ORNL summarized the barriers that prevent data from being archived.

            The methodology used for this state-of-the-practice review attempted to first capitalize on the existing information, despite the fact that this information might not serve the specific needs of this study. Leveraging on the existing information, we then sought the specific data needed for this study through other means such as site visits and telephone interviews.

            The first phase of the analysis inventoried which agency was archiving and using what ITS-generated data and for what purposes. A sweeping, but not-so-specific inventory of the state-of-the-practice on archiving and using ITS-generated data was developed using information collected in the ITS Deployment Tracking Surveys. Since this survey is not designed specifically to address issues addressed by this study, it does not provide all of the desired information. Other supplementary information sources were used – such as information reported in the Intelligent Transportation Systems (ITS) Projects Book - 2000, and findings from a literature search.

            Findings from this tier of analysis helped identify a number of specific case studies for more in-depth examination. The combination of site visits, telephone interviews and literature review was used to more comprehensively understand the issues that were absent from the existing survey data and/or documents. Example issues include: how and how frequent data are archived, in what format the archived data are stored, how archived data are accessed by others, for what purpose the archived data are used, barriers that hinder sharing the archived data, etc.

            The final goal of this project is to provide information that can be used to develop future Technical and Institutional Synthesis Studies outlined in Wave II of the ITS Data Archiving Five-Year Program Description. Opportunities for using archived ITS-generated data are formulated by matching the potential usefulness of archived ITS-generated data to data gaps and data needs that have considerably hindered the improvement of our nation’s transportation systems. Rather than being complete in identifying all possible opportunities, this project focuses on exploring the utility of archived ITS-generated data in meeting the data needs that have the greatest and the most immediate potential for improving the planning, safety, and operations and maintenance of our surface transportation systems.

3.2 INFORMATION SOURCES 

            A combination of information sources was used for this study. In January 1996, the then-Secretary of Transportation set a goal of deploying the integrated metropolitan Intelligent Transportation System (ITS) infrastructure in 75 of the nation's largest metropolitan areas by 2006^3.1:

"I'm setting a national goal: to build an intelligent transportation infrastructure across the United States to save time and lives, and improve the quality of life for Americans. I believe that what we do, we must measure . . . Let us set a very tangible target that will focus our attention . . . I want 75 of our largest metropolitan areas outfitted with a complete intelligent transportation infrastructure in 10 years^3.2."

            In order to track progress toward fulfillment of the Secretary's goal for deployment, the U.S. Department of Transportation (USDOT) implemented the metropolitan ITS deployment tracking methodology. This methodology tracks deployment of the nine components that make up the ITS infrastructure: (1) Freeway Management; (2) Incident Management; (3) Arterial Management; (4) Emergency Management; (5) Transit Management; (6) Electronic Toll Collection; (7) Electronic Fare Payment; (8) Highway-Rail Intersections; and (9) Regional Multimodal Traveler Information.

            The deployment tracking data were gathered through a set of surveys. These surveys targeted state, county, and local agencies within the metropolitan planning boundary for 78 of the largest metropolitan areas. Fifty-three of these 78 areas are among the top 68 most congested metropolitan areas^3.3. Table 3.1 lists the 78 areas. The surveys gather information on the extent of deployment of ITS infrastructure and on the extent of integration among the agencies that operate the infrastructure. The survey was conducted in the years 1996, 1997, 1999 and 2000^3.4.

Table 3.1  Seventy-Eight Metropolitan Areas in the Deployment Tracking Survey

                  ^* Based on 1999 Texas Transportation Institute’s Congestion Index.

            Approximately 2,000 surveys were sent in 1999, over half of which were sent to public safety agencies for emergency management information – fire, police and ambulance. Local transit agencies were contacted for transit information, and state DOTs provided freeway management and freeway incident management data. Arterial management surveys were sent to state, county, and city agencies that operated traffic signals. Toll authorities were contacted to provide electronic toll collection data. Additionally, surveys were sent to the Metropolitan Planning Organizations associated with each metropolitan area. The overall return rate in 1999 was around eighty-six percent.

           Although the data gathered from these surveys in many cases exceed the needs to track the deployment, additional data were gathered to meet specific data requirements for several USDOT functional users, including detailed information concerning incident and transit management, deployment planning procedures, and data archiving. As a result, the deployment tracking database is a significant source of general information concerning ITS deployment in the nation’s largest metropolitan areas and, in particular, about data archiving. For example, the freeway management survey contains questions about the following types of data: facilities, functions, and staffing of traffic management centers; traffic data collection technologies; data dissemination technologies; traffic control devices; use of standards; types of data collected and archived; and extent that data are shared with other agencies. Questions concerning freeway data collection and archiving cover the following: traffic volumes, traffic speeds, lane occupancy, vehicle classification, vehicle location, ramp queues, ramp meter preemptions, metering rate, road conditions, weather conditions, and incidents. Similar data collection and archiving questions are included in the transit management and arterial management surveys.

            Many data elements collected in the deployment tracing surveys cannot be explicitly and readily identified as having any ADUS potential. For example, many data elements collected in this survey have safety implication but they are not explicitly and not conveniently labeled as “safety-related.” To further understand which data elements could be used for what safety analysis, and how (e.g., analyze the data with respect to its applicability to rural or urban safety issues), ORNL assessed this data source with respect to its ability to be used in any of the four applications. Moreover, survey results were analyzed to explore the potential of using ADUS to help meet Federal data reporting requirements (e.g, the Highway Performance Monitoring System, Fatal Accident Reporting System).

            Although these surveys contain a wealth of information on data collection and data archiving, they do not completely fulfill the goals of this project. Special approval was obtained from the Joint Program Office to contact a limited number of responding agencies in an attempt to further comprehend the issues of how archived data are being used, by whom, and the barriers to data archiving. Due to this deliberate decision to contact only a few agencies, findings reported in this memorandum should be considered as indicators of general trends, rather than as definitive conclusions.

            It should be emphasized that this assessment only focused on in-place ITS deployments and field operational tests that have generated data that have the potential of being used in applications other than what was originally intended. This stage of the assessment has not attempted to identify ITS deployments that have not, but could have, archived and shared ITS-generated data. Examples of the latter are ample, such as the I-95 Corridor FleetForward project, and the in-vehicle signing system for school buses at railroad-highway grade crossings^3.5.

            In addition to data collected in the deployment tracking surveys, ORNL used information reported in USDOT’s annual report, Intelligent Transportation Systems (ITS) Projects Book - 2000. This report provides a comprehensive inventory of all ITS projects categorized in three areas: metropolitan, rural/statewide and commercial vehicle. Furthermore, a literature search was conducted to identify case studies and innovative uses of archived ITS-generated data.

            To maximize the benefits of the case studies, six sites were selected based on the criterion that each of these sites has deployed ITS components that cross-cut at least two of the six ADUS topical areas (i.e., traffic/roadway, safety, statewide/rural, MPO, transit, commercial vehicle operations). Table 3.2 lists the six proposed case studies and the corresponding topical areas covered by the case study. The site visit to Los Angeles was productive in that considerable information was collected by directly interacting with local agencies and personnel. That site visit not only set a model for other site visits but also suggested that telephone interviews could be equally productive, less costly, and less burdensome to the to-be-visited agencies. A template was then developed to guide the subsequent telephone interviews (Figure 3.1). The case studies are discussed later in this report.

                        Table 3.2 Proposed Case Studies and the Pertinent Topical Areas

^a     Nashville was eliminated from the list due to the lack of sufficient ITS deployments for a reliable ADUS assessment.

^b      Lack of sufficient ITS deployment, Smoky Mountains National Park was replaced by Branson National Park. 

Figure 3.1 ADUS issues to be address in phone interviews

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