The Simulation And Evaluation Of Improved Work Zone Layout Based On Entropy

At present, highway maintenance and repair work has been heavier, due to the increasing traffic and more trucks which caused damage to the road. Some areas of the original road have to be occupied because of construction, and the reduced areas lead to a lower capacity, more frequent road congestion and longer travel delays. Therefore, the unimpeded and safety of highway work zone has become a worldwide problem. In this paper, road conditions have been simulated by VISSIM simulation software. The speed limit control and spatial layout scheme has been raised to solve the congestion and travel delay at the upstream transition area. Entropy value method is used to evaluate the result of the scheme.Firstly, traffic data is collected on Hebei province freeway, traffic volume and traffic composition on different freeways, and the presented type and layout scheme of work zone in our country. The characteristics of the vehicle merging and control strategy in America are introduced in this paper. The improved work zone layout and variable speed control is contained based on the advanced foreign technology and programs.Secondly, features, functions and classification of traffic simulation are introduced briefly. VISSIM simulation theory and simulation processes are described in this paper. The new layout scheme of highway is proposed, which closed a short way in the ultra-lane of upstream transition section, and simulation results are gained via VISSIM. The variable speed limits control scheme is put forward, which turn the traditional fixed speed limits into variable speed limits. A reasonable distance is determined between the speed limit signs and detector based on traffic wave theory. VISVAP module and VISSIM microscopic simulation software is applied to simulate the operating conditions under different limiting options in work zones and select appropriate evaluation parameters.Finally, evalution index system based on entropy is established. The simulation results of highway improved space work area layout and speed control scheme were evaluated to gain the entropy and weights of indicators. The two schemes are proved better than the traditional one through program evaluation scores.The paper seeks to reduce the recurrent vehicle delay at merging zone on freeways, the finale results show that traffic efficiency, capacity and security is improved obviously by both schemes.