An understanding of drivers' en route decisions may help design strategies for ameliorating traffic congestion. A survey of downtown Chicago automobile commuters was conducted to investigate en route diversion in response to incident-induced congestion. The effects of factors such as source of congestion information (radio traffic reports versus observation), driver and trip characteristics, route attributes, and environmental conditions on driver response to delay were explored. En route diversion behaviour was found to be influenced by source of traffic information, expected length of delay, regular travel time on the usual route, number of alternate routes used recently, anticipated congestion level on the alternate route, gender of the driver, residential location, self-evaluation statements about risk behaviour (personality), and stated preferences about diverting.The results show that realtime traffic information broadcasts provide a basis for en route diversion decisions. Further, length of delay and perception of traffic congestion on the alternate route also influence such decisions. Short-term improvements in realtime traffic information should focus on disseminating information about length of delay due to incidents and the congestion levels on the alternate routes surrounding the incident. This action requires monitoring traffic conditions on the alternate routes along major roadways. Providing clearer information on delays and congestion will help drivers make more informed route selection decisions.
Samenvatting