A novel conditional cell transmission model for oversaturated arterials

The objective of this work is to develop a novel feature for traffic flow models,when traffic queues on two-way arterials periodically extend until then they block an upstream signal in oversaturated conditions.The new model,proposed as conditional cell transmission model(CCTM) has been developed with two improvements.First,cell transmission model(CTM) is expanded for two-way arterials by taking account of all diverging and merging activities at intersections.Second,a conditional cell is added to simulate periodic spillback and blockages at an intersection.The results of experiments for a multilane,two-way,three-signal sample network demonstrate that CCTM can accommodate various traffic demands and accurate representation of blockages at intersections.The delay of left turns is underestimated by 40 % in moderate conditions and by 58% in oversaturated condition when using the CTM rather than CCTM.Finally,the consistency between HCS 2000 and CCTM shows that CCTM is a reliable methodology of modeling traffic flow in oversaturated condition.

The objective of this work is to develop a novel feature for traffic flow models, when traffic queues on two-way arterials periodically extend until then they block an upstream signal in oversaturated conditions. The new model, proposed as conditional cell transmission model （CCTM） has been developed with two improvements. First, cell transmission model （CTM） is expanded for two-way arterials by taking account of all diverging and merging activities at intersections. Second, a conditional cell is added to simulate periodic spillback and blockages at an intersection. The results of experiments for a multilane, two-way, three-signal sample network demonstrate that CCTM can accommodate various traffic demands and accurate representation of blockages at intersections. The delay of left turns is underestimated by 40 % in moderate conditions and by 58% in oversamrated condition when using the CTM rather than CCTM. Finally, the consistency between HCS 2000 and CCTM shows that CCTM is a reliable methodology of modeling traffic flow in oversaturated condition.