Analysis of Route Travel Time Variation of Road Network Suffering Traffic Incidents

Analyzing route travel time variation of road network suffering traffic incidents can provide reliable decision supports for the incident management of advanced traffic management systems. Taking into consideration the randomness of travelers' daily route choice when incidents with a duration of several days occurs, a random dynamical assignment model was proposed to describe the route travel time variation of the road network system under such occasion based on the dynamical adjustment process with route flows subjecting to a joint probability distribution. Then, the model was applied to an example network to confirm its feasibility. The results show that when the traffic incident duration prolongs 10 more days, the average route travel time increases 0.24%. Compared with normal links, the critical link that suffers the traffic incident causes the average travel time to increase 3.07%: When the link capacity degrades 10%, the average travel time increases 2.53%. The necessary time for the network system recovering to equilibrium after the clearance of incident is greatly affected by the link with traffic incident. The recovery time of the critical link suffering incident is about 4 times longer than that of normal links.