Effect of left-turning traffic signal lights on vehicle motion delay at intersection

In recent years, left turning traffic signal lights have been installed at some main intersections in big cities in China. A model describing the delay in vehicle motion at an intersection with left turning lights is established, and the stochastic processes in the cases of the uniform distribution and negative binomial distribution for the vehicles passing through the stop line are analyzed. The model was examined with a typical intersection in Shanghai. The comparision of the presented model with the stop line model and the conflicting point model proves that the present model is applicable. The results show that the application of the left turning signal lights could enhance the traffic capacity and to reduce the conflicts or accidents at intersections.