Cross-cutting Issues

In this paper, we present two applications of a new and compact representation of link exit times. The first application is efficient communication of travel time functions between different geographical locations. The second is to solve the one-to-all fastest path problem in dynamic networks. We develop the new space efficient representation that exploits the nature of link travel times in dynamic networks. We present its application in communication of travel time functions that lies at the heart of Intelligent Transportation Systems operations. We then describe the fastest path algorithm and illustrate its working on a simple network. This algorithm performs logical operations on 0 and 1 bits only. Furthermore, one could develop parallel algorithms that operate at the bit-level on registers. The ideas behind the development of this algorithm are extendable to the development of algorithms operating at the bit-level, to solve other variants of dynamic shortest path problems as well as other dynamic network flow problems. The developments of this paper then open new horizons in the research area of communication of dynamic functions and development of solution algorithms for dynamic network problems.

Massachusetts Institute of Technology

Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

This paper uses the example of the Maryland State Highway Administration’s (MDSHA) development of a new traffic management system to explore some of the possible pitfalls and solutions to coordinating transportation management systems. The first section provides background on Maryland’s Coordinated Highways Action Response Team (CHART) system upgrade, which will improve Maryland’s traffic management and information system capabilities. The second section describes the overall goals, issues, and development approach. Maryland’s goals for CHART II include development of the traffic management and information system capabilities needed now and development of capabilities to share overall transportation management information, especially as it relates to incidents, between all transportation modes and agencies. The primary issues considered relate to the diversity in both the business functions and the development funds and timeframes within the many state transportation modes and agencies. The development concept is based on a two-prong approach involving 1) maintaining the separation between distinct business functions to prevent unnecessary complication and 2) coordinating these distinct systems through a well-planned communications and data architecture. This approach is intended to avoid the trap of attempting to create one giant do-it-all system that will become too complex to succeed.

The conclusion to this paper lists recommendations specific to development of CHART II for MDSHA. However, these recommendations can be restated to apply to any state that is wrestling with similar challenges:

• Maintain a clear business focus when developing any new transportation management system,
• Develop a statewide network and data architecture to tie together the many diverse systems within a state, and
• Stay involved and informed about the Intelligent Transportation System (ITS) standards that will aid in connecting the diverse transportation systems within a state and region.

The Johns Hopkins University

PB Farradyne, Inc.

The University of Maryland - The Center for Advanced Transportation Technology

Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

While extensive ITS technology is being deployed in the field, it remains difficult to perform formal evaluation of the benefits obtained from the implementation of the technology due to the lack of available evaluation tools. We propose a methodology that uses a simulation/optimization approach to develop a performance versus cost tradeoff analysis curve. In particular, we are evaluating ITS sensor and control technologies such as cameras, ramp metering, loop detectors, etc. Employing CORSIM, a traffic simulation tool, we determine the “optimal” ITS deployment and implementation strategy for a particular budget using a pseudo random search technique. This analysis is repeated over a range of budgets to determine the nature of the cost/performance tradeoff curve. We demonstrate this approach with a six-mile section of interstate in the Hampton Roads region of Virginia.

University of Virginia - Department of Systems Engineering

Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

The project described in this paper was funded by the ITS IDEA Program of the National Academy of Sciences – Transportation Research Board in Washington DC. This project, categorized as a Product Test, involved the system development and testing of a communication device based upon the ReFLEX Narrowband PCS technology commonly used in two-way pagers. The pager-based communication device was tested with three different remote sensors in the Boston Metropolitan area with assistance and support from the Massachusetts Highway Department. This product is cost effective for transmitting data from Highway Performance Monitoring System sites, and in event-based data transmissions such as incidents, weather, equipment failure, etc. It can be a cost-effective alternative in typical ITS application in situations when traditional methods such as telephone, spread-spectrum or cellular either are technical infeasible or have high installation costs.

TRAFINFO.COM, Inc.

Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA

This paper reports a successful demonstration of the use of microwave Doppler radar for all-weather regional surveillance of commuter traffic. Extensive traffic measurements were made from the Empire State Building in New York City using a small marine radar modified to perform high resolution Doppler measurements. The radar was able to measure traffic flows, with extremely precise speed determination, out to distances of over 10 km. The radar concept, when fully developed, is expected to add significant and cost-effective enhancements to advanced traffic management systems by providing surveillance of commuter arteries in metropolitan regions from a single elevated site or, at most, a few elevated sites

Weissman Science & Engineering Co.

XonTech, Inc.

Dunn Engineering Associates

Presented at the 10th ITS Annual Conference and Exposition, May 1-4, 2000 Boston, MA