Jacob Dirk Vreeswijk

Energy efficient traffic management and control - the eCoMove approach and expected benefits

Transportation is an important contributor to environmental problems like declining air quality. Current traffic measures seek to optimize travel times, but fall short on the ideal of an ecologically friendly traffic system. The European research project eCoMove aims to reduce the overall fuel consumption in traffic by 20 percent by means of energy efficient driving behavior and energy efficient traffic management and control. This paper contributes to the understanding of the feasibility of this goal. Vehicle-to-vehicle and vehicle-to-infrastructure communication is a key element in the vision of eCoMove. In this paper the eCoMove concepts are presented by means of an in-depth look on the eco Adaptive Balancing and Control system. Preliminary studies on rerouting, green priority and speed advice at signalized intersections indicate signification environmental benefits.

Drivers' perception of route alternatives as indicator for the indifference band

Although travel time is probably one of the most important attributes in route choice, the shortest time route is often not the preferred route, according to several studies in the literature. This study tries to explain this finding by testing the hypothesis that choice makers may be able to estimate travel times correctly for routes that they prefer but are biased against alternatives even if these are faster. For a few choice sets of routes in the city of Enschede, Netherlands, respondents were asked to choose a route and provide their estimated travel times for both the preferred and the alternative routes. These travel times were then compared with actual travel times from a license plate study. The comparison confirmed the hypothesis. For chosen routes, perceived travel times correspond quite well with actual travel times on average, whereas for routes not chosen, perceived travel times are overestimated by 3 to 4 min on average. These results show that drivers are not able or do not want to evaluate routes objectively. This finding implies that within an indifference band of route delay or travel time inequality of on average 3 to 4 min, drivers are probably not willing to alter their route choice, even if the traffic situation, induced, for example, by traffic management measures, changes in a negative way for their preferred route.

Toward effective strategies for energy efficient network management

Trade-offs in efficiency, equity and acceptability arise as a central feature in traffic management. Todays urban traffic network management strategies focus on overall system performance and often overlook the interests of the individual road user. In addition, the emphasis is on travel time savings and scarcely on the environmental impact of traffic. This research contributes to knowledge on the trade-offs between collective and individual interests (multi-level) and accessibility, and the environment (multi-objective). The objective is to integrate these trade-offs in new strategies for energy efficient network management and evaluate these strategies with the ecoAdaptive Balancing and Control application of the eCoMove project. This paper discusses findings from literature review and presents the design of a Ph.D. research.