Research On Traffic Safety Of Freeway Reconstruction Project

Along with the rapid social and economic development in China, freeways that were constructed early and used for many years would face the problems of being unable to meet the need of transportation demand and being reconstructed by widening roadway in order to meet the requirement of traffic demand. The technology of freeway reconstruction would be more and more important in sustainable development for freeway transportation. In consideration of the key role of freeway in transportation the freeway reconstruction scheme of reconstructing while opening for traffic on freeway has significant social and economic benefits. The traffic safety facilities in freeway reconstruction are the key to ensure the successful completion of the reconstruction.This thesis first analyzes the two factors that have the main impact on freeway traffic safety, secondly comparatively studies the relationship models between speed and accident as well as speed and severity of accident, and finally the dynamic relationship models between speed and drivers'visual acuteness and judgement, and the dynamic relationship models between speed and vehicular brake distance. The two equations of safe spacing computation for vehicular travelling on freeway are derived theoretically, and then the statistical relationship bewteen trucks and traffic accidents is analyzed and its root cause is profoundly studied.Based on the above two main factors impacting freeway safety the traffic safety precaution measures for freeway reconstruction projects are chiefly the speed control and truck diversion ones. In order to provide alternatives that can be used in freeway reconstruction projects the various speed limits and speed surveilance measures and their validity are fully studied. This thesis emphasized on the studies on the placement gaps between successive road traffic signs as well as the size of Chinese characters on plate of traffic signs, the equations of calculating the placement gaps between successive road traffic signs and the sizes of Chinese characters on plate of traffic signs by considerations of speed, roadway width, the palcement ways of traffic signs, as well as the message volume of traffic signs are obtained. As for the control measures of truck diversion the truck impacts on the capacity of freeway reconstruction section is analyzed and then the traffic sign placement methods for the start diversion point and the mid control point of freeway reconstruction segment are proposed, and the variable message signs and road advisible radio systems are intrduced into the freeway reconstruction projects.Finally the thesis synthetically described the traffic safety facilities that applied in LianHuo freeway reconstructed project.and discussed the speed control measures, large truck diversion control measures, temporal separation facilities, night safety precautions as well as the accident disposal methods used in LianHuo freeway reconstructed project...