Personal Mobility

This study investigated the pre-trip and en route decision processes that typify driver decision making about route choices and route diversion. Verbal commentary methods were used to expose on-going perceptual and evaluative activity while participants made normal trips, unaccompanied, in their own vehicles. The trips included morning home-to-work commutes, evening work-to-home commutes, evening or weekend trips to an unfamiliar shopping mall, and weekday, off-peak trips to a downtown business area. Twenty-four paid participants took part, all in the greater Washington, DC, area. Each participant received extensive training, via a training video and a supervised training session, before being provided with an in-vehicle video recording system and recording specified trips. The information collected included pre-trip information sources and decisions, and continuous en route commentary on information sources, decisions, questions, strategies, major concerns, information needs, and errors. At the conclusion of each trip, additional information was collected on the driver.s perception of various aspects of the trip and the related information sources and needs. Each participant also completed a set of spatial ability tests at some point during the study. The analysis revealed a variety of findings regarding the information drivers use or desire, and its timing or location. Differences among trip types and driver categories (familiarity, age, spatial ability) were also noted. The findings are related to information needs that may be addressed by Advanced Traveler Information Systems (ATIS).

Westat

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

This paper reports on traveler (primarily commuter) perception of commercial radio traffic information. Data includes opinions expressed by participants in two efforts undertaken by the Michigan Department of Transportation (the DIRECT Operational Test and the Southeast Michigan ITS Expansion Evaluation). In both instances, participants were selected because they travel the expressway system in the Detroit Metropolitan area. The primary objective of the paper is to suggest ways in which commercial radio traffic information can be improved upon. The paper is divided into seven sections: data sources, study participants, participant use of commercial radio traffic information, subject rating of the performance of commercial radio traffic information, subject rating of the benefit of using commercial radio traffic information, subject suggestions of ways to improve the system under consideration, and implications for new information systems.

At the outset of the study, some members of the evaluation team thought that some form of new information service could potentially supplant or supersede commercial radio as a source of traffic information. Contrary to this notion, the study revealed that drivers very much appreciate and rely on commercial radio as a source of traffic information. Nevertheless, drivers do find some fault with commercial radio-based traffic information and have suggested a variety of ways to improve the usefulness of this information. The observations herein lead to a conclusion that a personalized route-specific interrupt or “push” system could be a valuable and readily accepted complement to commercial radio traffic information.

University of Michigan - Intelligent Transportation Systems Research Laboratory

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

Ramp meters in the Twin Cities have been the subject of a recent test of their effectiveness, involving turning them off for 8 weeks. This paper analyzes the results with and without ramp metering for several representative freeways during the afternoon peak period. Seven performance measures: mobility, equity, productivity, consumers’ surplus, accessibility, travel time variation and travel demand responses are compared. It is found that ramp meters are particularly helpful for long trips relative to short trips. Ramp metering, while generally beneficial to freeway segments, may not improve trip travel times (including ramp delays). The reduction in travel time variation comprises another benefit from ramp meters. Non-work trips and work trips respond differently to ramp meters. The results are mixed, suggesting a more refined ramp control algorithm, which explicitly considers ramp delay, is in order.

University of Minnesota

Presented at the ITS America Annual Conference and Exposition, May 19-22, 2003 Minneapolis, Minnesota

Dynamic Traffic Assignment (DTA) is perceived as a major ITS initiative to manage congestion. DTA algorithms seek to guide “smart cars” along paths to their respective destinations so as to disperse traffic demand over a network in a manner that minimizes vehicle hours or trip travel times. DTA algorithms must be tested before deployed. This paper describes a microsimulation model designed to interface with any DTA algorithm, which simulates the operational performance of traffic comprised of a mix of “smart” cars equipped to be guided during their travel, and those not so equipped. Results obtained by the model simulation a DTA traffic environment are presented.

KLD Associates, Inc.

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

The Traveler Information Center (TIC), known as SmarTraveler, is one element of the Orion Program for deploying Intelligent Transportation Systems (ITS) technologies in the Twin Cities metropolitan area. The TIC is an example of an Advanced Traveler Information System (ATIS) providing real-time traveler information via telephone and Internet services. It has been operational since November 1998. The project is under the overall supervision of the Minnesota Department of Transportation (Mn/DOT) and its management consultant/private sector partner, Lockheed Martin of Canada (LM). The TIC is owned, managed, and operated by SmartRoute Systems under subcontract to LM.

The purpose of this paper is to present the evaluation results which tested the accuracy of the data being provided by the TIC. The hypothesis of the evaluation is that the TIC is providing reasonably accurate information, and that the quality of this information will improve over time. This hypothesis was measured by conducting travel time runs on designated routes covered by the TIC, and comparing the travel conditions observed with the conditions reported by the TIC at the beginning and the end of the travel run. The measures evaluated for accuracy were travel time, accidents, incidents (breakdowns), and construction. The travel time runs were conducted in the spring and fall of 1999.

Cambridge Systematics, Inc.

URS

Minnesota Department of Transportation

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