Freeway Lane Restriction Research Based On Truck Traffic Impact

The high truck proportion is one important reason for serious traffic congestions and accidents, which frequently occur on freeways whose traffic volumes are lower than capacity in China. On one side, when cars and trucks travel together, the low-speed trucks will obstruct the high-speed cars, which will reduce the traffic efficiency. On the other side, due to the dramatic speed difference of cars and trucks, the lane-change overtaking is frequent, which greatly increases traffic conflicts. Aiming at this problem, the paper focuses on utilizing lane restriction strategy to improve traffic efficiency and safety.Former research mainly focuses on truck lane restriction, but this thesis first proposes to adopt car lane restriction and truck lane restriction together. After comparing traffic operations of four-lane, six-lane and eight-lane dual carriageway freeways under different lane restriction strategies by traffic simulation, it is found that compared with only restricting trucks, restricting both cars and trucks can improve traffic efficiency and safety better. Then, after identifying the optimum lane restriction strategies of different freeways, the thesis analyzes traffic operations under different driver compliance rates and gradients. The simulation indicates if the driver incompliance rate can be limited within certain ranges, the restriction strategies still can effectively improve traffic efficiency and safety. And in slopes, because the trucks run slower and the corresponding obstruction effect of trucks is more evident, the lane restriction strategies do a better job.