Importance of spillback modeling in assessing ITS

This paper discusses the importance of spillback modeling in assessing the impacts of dynamic traffic management. Specifically, the paper compares the influence of route information in a simulation with spillback and without spillback modeling. The considered case entails an evacuation of a city (circa 250,000 cars). The results indicate that in the non-spillback simulation, the network performance is indifferent for route measures, whereas in the more realistic simulation with spillback, there are differences between different types of information provision. It is concluded that a traffic model without simulation of spillback not only gives an underestimation of evacuation times - which is obvious -, but more importantly it completely underestimates the effect that can be obtained by route information. The travel time gain according to the non-spillback model is 18%, whereas the spillback model predicts 17% reduction of travel time. It is also shown that for the case at hand, the congestion caused by spillback can be avoided by providing appropriate information