1.1 Archived Data Management Systems
Archived Data Management Systems (ADMSs) are information management systems with decision support capabilities that implement the requirements found in the Archived Data User Service (ADUS). ADUS is one of 33 user services identified within the National ITS Architecture (henceforth, "the Architecture") that were created to document (in somewhat general terms) what an ITS application should do from the user's perspective. A broad range of users are considered, including the traveling public as well as many different types of system operators. User services form the basis of the Architecture development effort.
ADUS was developed as an addition to the original Architecture as a way to capture for later use real-time information used for ITS control strategies. One of the features of ADUS that distinguishes it from other user services is the large number (14) of stakeholder groups. These stakeholders include public transportation agency personnel (e.g., planners, air quality analysts, researchers, transit operators, and safety administrators) as well as private sector groups. By using archived ITS data, data collection costs for stakeholder applications can be reduced. Further, the detailed nature of ITS-generated data allow for more accurate analyses and make possible many applications that could not have been undertaken except at substantial cost. Figure 1 displays several examples of how a single subset of archived data - travel monitoring data - support ADUS stakeholder functions. ADUS relies on other ITS functions to provide data. This requires that close coordination be achieved with other ITS standard efforts.
Figure 1. Archived Travel Monitoring Data Serve the Applications of Multiple Stakeholders
One of the stakeholder groups identified in the development of ADUS is operations personnel. They are crucial to the success of ADUS in that they control the collection of data that form the basis of the archives. Moreover, operations personnel are also major beneficiaries of ADUS. Early ADUS documents postulated that archived data would promote improved operations by helping to determine control strategies (e.g., timing of ramp meters and traffic signals; deployment of incident management equipment, etc.) and in evaluations of programs. While these original purposes remain valid, it is becoming increasingly clear that operations personnel will accrue additional benefits from ADUS as ADMSs become more widespread and grow in sophistication.
Several recent events have greatly increased the importance of ADUS for ITS deployments. First, the need to do Federal performance benchmarking as a way to track program effectiveness has been identified by FHWA. Second, related to Federal benchmarking is the provision of detailed data for operations planning. Operation of the transportation system has become the primary focus of many transportation organizations including FHWA and ITE. ADUS provides the highly detailed data necessary to do operations planning at a high resolution level (such as evaluations, performance measurement, and deployment adjustments), especially considering the expense of dedicated data collection efforts. Third, closing the Advanced Traveler Information System (ATIS) data gap and producing the next generation of ATIS products requires ADUS. A sound and detailed historical record of system performance is needed for ATIS purposes, especially as products become more sophisticated. For example, short-term congestion forecasts are seen as a highly marketable product, but these must rely on analysis of historical congestion trends to be credible.
As a user service, ADUS is a concept rather than a tangible system. As noted previously, an ADMS is the system that implements the concepts embedded in ADUS. At its core, an ADMS is an information management system that is actively maintained following standard information technology principles. Advanced forms of ADMSs may include applications that achieve the functionality of a decision support system, but their primary purpose is to collect, process (including quality control, aggregations, and data transformations), store, and disseminate data for a wide variety of existing and emerging applications.
1.2 Background On The TMC Applications Of Archived Data Operational Test
1.2.1 Project Goals
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 objective from the original Request for Application (RFA) was stated as:
The objective of this operational test is to study how transportation management center (TMC) operational practices and procedures can benefit through the applied use of archived data from highway-based and/or transit-based ITS sources. This effort will consider how specific TMC functions can be enhanced through performance measures and analytical techniques enabled through archived data. The results of this operational test will be used to support the development of guidance for applying archived data to enhance transportation management center operations, practices and procedures.
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 current state of the practice in designing ADMSs.
With regard to operations, algorithms were to supporting various Advanced Traffic Management Systems (ATMS) and ATIS functions were to be considered. The RFA stated:
The ATMS and ATIS functions that may be supported include, but are not limited to, the following:
- Performance measurement
- Arterial performance measurement using transit-based archived data
- High-occupancy vehicle (HOV) lane management
- Signal system management
- Ramp metering management
- Incident management
- Work zone operational impacts measurement
- Weather-based traffic management response
- Special events management
- Disaster/emergency response management
- Travel-time prediction along route segments
- Travel-time prediction between points
- Travel-time reliability predictions
- Transit reliability and performance assessment
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:
[The project should...] Determine how the operational performance of the TMC changes as the archived data are applied. Although each TMC has unique operating characteristics, the operational performance can be gauged by establishing performance criteria. Examples of performance criteria may include, but are not limited to, the following:
- Travel-time reliability
- Travel-time prediction error
- Percent reduced congestion in particular locations
- Percent reduced vehicle crashes
- Reduced response time to incidents
- Increased average speed during peak periods
1.2.2 Project Development
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 which is located on the campus of UVA.
ADMS Virginia was deployed starting with the Hampton Roads area. The Hampton Roads participants in the process included:
- The Hampton Roads Smart Traffic Center (HRSTC)
- The Hampton Roads Planning District Commission (HRPDC)
- The Hampton Roads Transit (HRTransit)
- The VDOT Central Office, Mobility Management Division (MMD) and Air Quality Planning.
The project deployment was divided into four builds with incremental support of the above 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 areas.
The four builds of the project may be summarized as:
- Completion of the core STL infrastructure
- Included detector and incident data collected at the HRSTC
- A simple, non-graphic interface will be provided for these services:
- Historical data query at user-selected levels of aggregations
- Data Quality Assessments; Abnormality Checks; and Data Imputations
- Completion of the graphical user interface -- a map interface improved the user-friendliness of the system, allowing input and output through "point and click" selections on the map
- Added data from the traffic monitoring systems (TMS) continuous count stations and weather databases
- Addition of services:
- Mobility Measures of Effectiveness
- Traffic Fundamentals
- Evacuation Planning Support
- Air Quality Modeling Support
- Completion of the final system with all the required interfaces
- Added weather data from additional locations and arterial signal system data from City of Norfolk
- Addition of services:
- Transportation Planning Support
- Incident Management Support
- Transit Support
- Modeling/Simulation Support - added the ability to download data in a format compatible with the DynaMIT simulation model input requirements
- Adoption of the ADMS to the Northern Virginia District of VDOT (NoVA)
UVA directed the software development effort with Open Roads providing the software engineering. Highlights of the development approach used by the project team included:
- A systems engineering approach was applied that included defining system requirements by a stakeholder involvement process (Figure 2). Formal requirements documents were produced for each build.
- Rapid prototyping was employed to allow the stakeholders and developers alike to try and test the system during development, well before the final release.
- Stakeholder involvement was identified as an important aspect from the beginning, and they were repeatedly requested to provide ideas, review documents/demos, test prototypes, and report any abnormal findings.
Source: ADMS Virginia Draft Final Report, December 1, 2004
Figure 2. Systems Engineering Approach used in ADMS Virginia Development
1.1.3 Operations Centers
18.104.22.168 NoVA District of VDOT
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.
Loop detectors and pavement sensors that are embedded in the roadways prompt an automatic incident detection system that alerts Traffic Center controllers when and where there is likely to have been an incident. This equipment also gathers speed volume and occupancy data.
The Northern Virginia Smart Traffic Center Operators equipment inventory includes:
- 109 cameras
- 222 variable message signs
- 24 gates on I-66 HOV lanes for use during peak travel hours
- 21 gate groups on I-95/I-395 for reversible HOV lanes
- 25 ramp meters for inside the beltway on I-66 and I-395
- 30 lane control signals
- 23 vehicle classification stations
- 177 controllers with sensors and loop detectors
22.214.171.124 Hampton Roads Smart Traffic Center
The Hampton Roads region, located in Southeast Virginia, presents numerous challenges to the ongoing evolution and maintenance of a safe and effective transportation system. The region consists of ten cities (Chesapeake, Franklin, Hampton, Newport News, Norfolk, Poquoson, Portsmouth, Suffolk, Virginia Beach, and Williamsburg) and six counties (Gloucester, Isle of Wight, James City, Southampton, Surry, and York), with a current population of over 1.5 million people - an increase of 40% in 27 years. Over 100,000 military personnel live and travel in Hampton Roads, serving the Army, Navy, Marines, Air Force and Coast Guard. The area is also a prime vacation destination. On any given summer day, tourists can increase the region's population by as many as 100,000 people, and 85% are traveling by motor vehicle. Along with major tourist attractions, the region has the best natural deepwater harbor on the U.S. East Coast. More than fifty international shipping lines and over 400 commercial freight carrier companies operate in Hampton Roads, resulting in high volumes of commercial freight traffic. Over 560 thousand tractor-trailers arrive and depart from the three international marine port terminals annually.
I-64 is the primary Interstate route in the region; its eastern terminus is located here. Several Interstate "spur routes" are also located in the area:
- I-264 provides east-west travel from Chesapeake to Virginia Beach.
- I-464 provides north-south access.
- I-664 provides and additional water crossing on the west side of the region.
- I-564 provides access to the Norfolk Naval Station.
The region's limited number of waterway crossings, high population, increasing influx of tourists, waves of military personnel traveling to and from the numerous military bases, and high volume of freight movement cause traffic incidents and delays on a daily basis around Hampton Roads.
The Freeway Traffic Management System installed at the HRSTC 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 adds 31 miles of coverage on the peninsula and southside interstate (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 inventory for the STC will be over 275 cameras covering 113 miles of Hampton Roads freeways including I-64 from Lightfoot to Bowers Hill, I- 264/I-64/I-664 interchange; I-264 from Bowers Hill to Park Avenue, Virginia Beach; I-664 from Bowers Hill interchange through the Monitor Merrimac Memorial Bridge Tunnel to I- 64 interchange, Hampton; and I-564 from Terminal Boulevard, Norfolk to Gate 3 and 3A Naval Base.
126.96.36.199 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 and 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 University of Virginia and the Virginia Transportation Research Council. 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. The mission of the Smart Travel Lab is to:
- Conduct applied ITS research and development
- Provide technical support to VDOT's Smart Travel Program
- Develop and deliver innovative education and training programs.
The foundation of the laboratory is an OC-3 connection to the Commonwealth of Virginia's wide area network known as "Network Virginia." This connection is used to continuously transmit data and video from four Virginia Department of Transportation (VDOT) traffic control systems. These systems include:
- The Hampton Roads Smart Traffic Center (HRSTC), an freeway management system in Southeast Virginia that monitors and manages traffic on I-64 and I-264
- The Northern Virginia Smart Traffic Signal System (NVSTSS), a signal control system that manages nearly 1,000 intersections in the region.
- The Northern Virginia Smart Traffic Center (NVSTC), a freeway management system that monitors and manages traffic on I-95, I-495, and I-66.
- The Richmond Smart Traffic Center (RSTC), a freeway management system that monitors and manages traffic on I-64 and I-95.
1.3 Purpose of Evaluation
The primary purpose of the evaluation is to assess how well the ADMS Virginia project met its objectives, namely:
- 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
- How well the approach chosen for ADMS Virginia development resulted in a successfully operating system.
The next section of this report outlines specifics about the evaluation approach.