Drivers' perception of route alternatives

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 hypotheses that choice makers may be able to estimate travel times correctly for routes they prefer, but that they are biased against alternatives even if these are faster. For a few choice sets of routes in the Dutch city of Enschede, respondents were asked to choose a route and provide their estimated travel times for both the preferred and alternative routes. These travel times were then compared with actual travel times. The comparison confirmed the hypotheses. In only 41% of the cases the shortest time route was chosen. Travel times were generally overestimated while respondents on average overestimated travel times of non-chosen routes more than the travel times of chosen routes. Besides, familiar routes, orbital routes and most direct routes were preferred even when they had a higher travel time. These results show that drivers are not able or do not want to evaluate routes objectively which has important implications for traffic management practices.