RITA | ITS | Benefits: Drivers who use route-specific travel time information instead of wide-area traffic advisories can improve on-time performance by

Drivers who use route-specific travel time information instead of wide-area traffic advisories can improve on-time performance by 5-13%.

This study quantified the mobility benefits of listening to radio traffic advisories and compared them to those of a personalized traveler information service designed to provide door-to-door estimates of real-time travel times in the Washington, DC area. The data used to conduct the analysis were derived from 4410 traffic advisories broadcast on commercial radio, and several months of real-time corridor travel time estimates posted on the internet by an internet traveler information service (SmarTraveler.com). The impacts of each type of traveler information on travel-time reliability were then evaluated using a representative model of the Washington, DC regional transportation network.

To evaluate the performance of on-time arrivals between commuters provided with personalized route-specific travel time information and commuters provided with general radio advisory information, paired (yoked) driving trials were conducted using the HOWLATE (Heuristic On-line Web-Linked Arrival Time Estimator) technique. Each simulated pair had the same origin, destination, desired arrival time, and habitual route, but the subjects were not restricted to leave at the same time. One subject in each pair was provided with traveler information (i.e., radio reports or route-specific travel time information), and one was not. The radio listener had the advantage of making route modifications en-route, but the traffic information provided was vague and imprecise, and did not always cover the chosen route. The commuter who used route-specific travel time information was limited to pre-trip information; however, the information provided was more detailed with respect to departure time choice and route selection.

RESULTS

The results of the study showed that simulated commuters using route-specific travel time information typically made more effective route and trip timing decisions compared to users of broadcast radio traffic reports.

Overall, drivers who used route-specific travel time information were on-time 11% and 3% (AM and PM peaks respectively) more often than drivers who did not use either type of traveler information. In contrast, drivers who only listened to radio traffic reports were on-time 2% less often during these periods. Overall, drivers who used route-specific travel time information were on-time 13% and 5% (AM and PM peaks respectively) more often than users of radio reports.

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