Large Radius Of Circle Curve By Small Radius Circle Curve Linear Combination Ramp Speed Coordination Effect On Road Safety Research

In consideration of such factors as land use and construction cost in the design of highway interchanges, a few small radius ramp is often adopted. According to specification requirements, the design of the ramp rate and speed of the design of the main difference is often larger, especially the exit ramp and the transformation between the two high-speed main lane. Driving in the process of entrance ramp is a slow process. In order to ensure driving safety, the set speed changing lanes on the project Speed limit signs deceleration shock lines and some warning signs are often used. This, to a great extent, can make the vehicle from the high speed running condition of the highway line slow down to the designed ramp speed. In actual operation of the vehicles, before and after each ramp, flat vertical and horizontal line has a very big impact on the traffic safety, and designers tend to satisfy the requirement of specification according to the specifications requirement, and the use of the linear indicators. So they sometimes ignore the linear combination of the influence of train operation safety.This paper studies Wuxi hub interchange of Xicheng highway. The ramp linear indicators meet the requirement of specification. Under the condition of traffic safety facilities, the exchange area is still full of traffic accidents. This paper studies the actual running speed investigation, analysis, research, and safety evaluation, analysis of large radius of circular curve (or linear) pick up small swing radius ramp linear combination causes of truck traffic accident, think this kind of linear combination speed coordination is bad, and put forward to insert the circular curve of transitional nature to optimizes the design of the ramp of the linear combination of the linear solution. At the same time, combining with each other easily for the reconstruction and small radius of gyration ramp "compression", should not be proposed use lead to ramp the linear discontinuous inflection point connection mode.Finally, this paper through the vehicle running speed coordination evaluation to evaluate optimization of linear combination plan, verifies its feasibility and coordination. In order to further study the security of optimization scheme, similar to the linear combination of engineering example, Luoxi hub exchange further demonstrates the feasibility of the optimized scheme.