Coordinated Control of Urban Expressway Exit and Its Adjacent Intersection Based on Blocking Index

For an expressway which has a cross-section of main road and auxiliary road, and operates under the coordinated control method at the exit and its adjacent intersection, a model is based on blocking index that will demonstrate how to improve traffic efficiency of the area, including expressway exit and its adjacent intersections. The blocking indexes of expressway exit and it's adjacent intersection and the traffic states is also described. The coordinated control strategy can be carried on according to the traffic state of each control point and their mutual relations. The simulation of Vissim, as control strategy proposed is assumed and is proved to be effective.