In 2002, FHWA awarded a field operational test to the Virginia Department of Transportation entitled (VDOT) Traffic Management Center (TMC) Applications of Archived Data Operational Test. The intent of the operational test was to use archived data to effect transportation operations and management decisions. However, because an ADMS has value to a wide variety of stakeholders (14, as identified in the ADUS Standards Strategic Plan), the scope of ADMS Virginia was expanded to include applications for transportation planners as well as operators. The operational test was to build on the current state of the practice in ADMS design.
With regard to operations, algorithms supporting various Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS) functions were to be considered. Performance measurement of TMC functions was also emphasized in the RFA. Since performance measurement overlaps with the activities of transportation planners, their inclusion in the development process was a natural extension of the project's scope.
A team led by VDOT's ITS Division was selected to undertake this operational test. The project was named ADMS Virginia and this term is used throughout this report to reference the project. VDOT led the effort with a team that included the University of Virginia (UVA) Center for Transportation Studies (CTS) and George Mason University (GMU). UVA subcontracted the software development part of the project to Open Roads Consulting, Inc. (ORCI). The equipment necessary for the project is hosted at the Smart Travel Laboratory (STL), a joint facility of VDOT and UVA that is located on the campus of UVA.
The project design and deployment process was divided into four phases or "builds" with each successive build providing incremental support of the preceding services, rather than a single system at the end of the project period. The build approach was used to identify important features of the system and the interface, and to apply the institutional and technical lessons learned in the early builds to later builds. Builds 1-3 concentrated on developing a fully operational ADMS for the Hampton Roads area, with each successive build adding new functions. Build 4 entailed the expansion of the ADMS to the Northern Virginia District of VDOT (NoVA), which is located in the Washington, D.C. Metropolitan area. Builds 1 through 3 completed the requirements of the original scope of work for the FOT. At the completion of Build 3, sufficient funds remained to support a fourth build. A proposal was submitted to and approved by FHWA to extend the project scope and end date to develop Build 4, extending the system to incorporate data from NoVA. The system functionality developed in Builds 1-3 was the same for both regions.
Northern Virginia Smart Traffic Center
The Northern Virginia Smart Traffic Center is a high-tech communications hub situated in Arlington near the Pentagon. Controllers in this Traffic Center oversee more than 100 miles of roads. The system operates ramp meters, dynamic message signs (DMSs), highway advisory radio (HAR), and supports incident management activities.
The Center also monitors the usage of HOV lanes. Gates and gate groups are used to reverse HOV lanes to accommodate the traffic flow heading north and east in the morning and south and west in the afternoon.
Hampton Roads Smart Traffic Center
The Freeway Traffic Management System installed at the Hampton Roads Smart Traffic Center originally consisted of an extensive computer controlled, fiber-optic based communications and control network installed along 19 miles of the area freeways (I-64, -264 and I-564), 38 closed circuit television cameras, over 60 dynamic message signs strategically positioned across the entire Hampton Roads region, Wide-Area Highway Advisory Radio System, and Freeway Incident Response Teams patrolling over 70 miles of interstate in the region.
Phase 2 expansion of the Traffic Management System (TMS) was completed in March 2004. Phase 2 added 31 miles of coverage on the peninsula and southside interstates (I-64, I-264, and I- 564) with 80 additional cameras and other roadway detectors.
Phase 3 expansion is currently underway. When completed, the total system inventory for the STC will include over 275 cameras covering 113 miles of Hampton Roads freeways.
Smart Travel Lab at UVA
The Smart Travel Lab is a state-of-the-art facility that supports research and education in the rapidly emerging area of ITS. Using the latest information technologies, analysis, and modeling techniques, researchers in the lab are developing prototype systems and applications that promise to improve the effectiveness of ITS. It is a joint effort between the Department of Civil Engineering at the UVA and the Virginia Transportation Research Council (VTRC). The Lab serves as the direct connection to transportation management systems operated by the VDOT. This connection provides researchers with direct access to real ITS data and systems. This direct access has allowed the lab to provide substantive contributions to VDOT's ITS initiative, known as the Smart Travel Program.
Purpose of Evaluation
The primary purpose of the evaluation is to assess how well the ADMS Virginia project met its objectives, namely:
- How well the approach chosen for ADMS Virginia development resulted in a successfully operating system.
- How it supported TMC uses of archived data in order to effect improved operations.
- How ADMS Virginia was used to improve the functions of non-operations stakeholders.
Summary and Lessons Learned
- From a development perspective, ADMS Virginia is an exemplary archived data management system that can serve as a model for the rest of country. The Evaluation Team found the physical design of the system to have all of the main features of an ADMS as defined by FHWA, the National ITS Architecture, and current ITS standards. The relatively long list of users from outside of Virginia exploring the system's capabilities is another indication of the ADMS's successful deployment. In some cases, ADMS Virginia has broken new ground on the methods used to process and present data, including:
- Serious attention to post hoc data quality control, including the flagging of erroneous, suspicious, or missing data
- An advanced imputation algorithm to adjust for missing data
- Providing users with metadata, both about the archive structure and about processing steps (quality control and imputation)
- Fusion of traffic, incident, and weather data so that they are geographically consistent
- Repackaging of archived data into user-defined formats, such as AADT reports and simulation model inputs
- Professional software engineering and Information Technology principles aids ADMS development. The ADMS Virginia development team chose a highly structured approach to design and implementation that worked extremely well in terms of delivery (on-time and within budget). Highlights of this process that can be adopted by ADMS developers elsewhere include:
- User requirements process - heavy and early involvement of stakeholders
- Incremental "Builds" - which allowed users to see early versions of the system
- Structured programming, common web-based tools
- Metadata provision
- Map-based interface
- Searchable help
- Data quality and availability are the overriding features of an ADMS that will promote its usage. Potential users of an ADMS must have confidence in the quality of data before they will actively use the data for their applications. The Evaluation Team heard statements to this effect from most of the interviewees.
- Having event data in addition to traffic data stored in an ADMS enhances its usefulness. For the most part, the term "archived ITS data" is generally considered by the transportation profession to be traffic data from roadway detectors (volumes, speeds, and occupancies). However, fusing traffic data with event data (e.g., incidents, work zones, weather, and sporting events) - and even analyzing event data on their own - can have significant benefits for system operators and planners. HRSTC is using incident data to evaluate its incident response plan. ADMS Virginia also includes weather and special event data, and while the system does not currently include applications for them, future applications are likely to take advantage of them.
- From a planning perspective, a common drawback of currently deployed ADMSs (including ADMS Virginia) is the limited amount of highways covered by surveillance systems. Regional planning efforts require performance information on major highways throughout an area. In most cities, ITS is typically only deployed on major freeways. Expansion to all freeways and at least signalized arterials would provide additional information for planning purposes. A related issue is how to combine performance measurements from ITS with performance data from models - there is a concern that they may not be entirely compatible.
- TMC standard operating procedure manuals and operator contract stipulations must be considered during the ADMS design process - implementation of the system will likely require operators to engage in new activities. For example, because staffing of the Hampton Roads TMC is contracted out, the contract staff perform only those tasks assigned to them in that contract, or that can be directly measured as part of the evaluation of their performance (this is not a shortcoming of using contractors, which in the Hampton Roads case appears to work very well). New activities are time consuming and staff levels are negotiated under a particular workload assumption. Reporting on freeway performance has not been assigned to the TMC contractors, and is not used as a measure of the contractor's performance. Consequently, reporting on freeway performance cannot be automatically expected and may likely require a contract modification or some other change to the work agreement.
- If a software application (including an ADMS interface) is not part of the TMC software and displayed on the main console, its use is very limited. TMC operators are extremely busy when managing traffic in real-time. Any additional workload such as accessing an ADMS must be fully integrated into their normal operating software rather than an adjunct system. Similarly, the software must be capable of assembling information very quickly and with a minimum of input/query structure from the operator.
- Even with system availability and system performance concerns, ADMS Virginia stakeholders see a high potential for using the system in their applications. In Northern Virginia, system availability and the slowness of queries were the major impediments to usage during the evaluation period when the interviews were conducted. However, both these issues were addressed in Build 4.1 after the interviews were performed. The potential of the ADMS is not only recognized by end users but also by VDOT management, who are funding the maintenance and expansion of the system. The planners at HRPDC and the VDOT operators in Northern Virginia all expressed excitement at the potential of the ADMS, meaning that it may take a little time before that potential can be realized. This led the Evaluation Team to the following observation:
- It is likely that productive use of ADMS Virginia will have to wait for it become more fully populated with data and for users to gain experience with what the ADMS can do. In that sense, it may make sense to re-visit the evaluation in another 12 months to see what has changed.