Travelers' Compliance With Social Routing Advice: Impacts on Road Network Performance and Equity

Information-based demand measures using social routing advice are receiving increasing attention, as they are expected to be successful in reducing the traffic congestion. Such measures direct travelers toward routes that benefit the road network. As such, some travelers need to act socially and take a detour. This paper explores the impacts on network performance and equity that result from the application of a social routing service. We complement the existing work by using a large-scale real-world road network, by assessing impacts on the individual level and by discussing our findings in the light of observed individual compliance behavior obtained from a field experiment. Our results show that 3.6% of total travel time within our road network could be reduced when all trips are made in compliance with the received advice. However, based on the observed compliance behavior, a social routing service is expected to direct only a minority of travelers toward social routes. We show how the attained travel time savings vary with the assumed compliance rate, e.g., to achieve 50% of the potential travel time savings, about 30% of travelers need to be willing to take a detour. Moreover, we find that lower the compliance among travelers, the more the social travelers need to compensate for the selfish behavior of others by taking longer detours. Finally, we demonstrate that the impacts on network performance and equity highly depend on the spatial distribution of social travelers among origins and destinations.