Abstract
This work proposes an extended cell transmission model to describe traffic flow in urban networks. In the model, the paths of vehicles travelling toward a road link are depicted for the first time. Based on the model, a simulation approach is used to analyze the traffic jam formation caused by an incident under a scenario that travelers are informed of such an incident from advanced traveler information systems and some of them conduct a detour prior to entering the incident-induced congested roads. Simulation results reveal the influences of some major parameters on an incident-induced congestion formation. These parameters are the ratio of vehicles conducting a detour over the total ones and the amount of traffic flow driving to the blocked link in the traffic network. The results can be used to estimate the traffic jam size and traffic delay caused by traffic incidents.