Tunnel speed limit effects on traffic flow explored with a three lane model

This paper presents a three lane model to explore tunnel speed limit effects on traffic flow numerically. The model assumes traffic flow on each lane has its own density and speed, highlights the role of local homogeneity of traffic flow between adjacent lanes to express the net lane-changing rate more simply in comparison with the existing lane-changing modules. The tunnel speed limit effects involve in the aspects of travel time and density threshold of traffic shock formation due to the tunnel bottleneck. Based on the three lane model, a simulation platform is built that uses a 3rd order Runge–Kutta scheme to handle time derivative term, and a 5th order weighted essentially non-oscillatory scheme to calculate numerical flux. The simulation results show that the higher the tunnel speed limit, the larger the density threshold of traffic shock formation, but the shorter the mean travel time and tunnel mean travel time.