Research On Setting Up Parallel Truck Escape Ramps On Mountainous Expressway

Practices at home and abroad have proved that,truck escape ramp as a dedicated lane for vehicles with brake failure to drive away from the lane as soon as possible,decelerate to stop,and self-rescue lanes,it is one of the most important and effective engineering and technical measures to improve traffic safety on long and downhill sections.The research object of this article is the parallel truck escape ramp,whose longitudinal slope is consistent with the main line.It inherits the downhill slope emergency escape ramp which can better adapt to the terrain conditions,the amount of filling works is small,and the location is relatively easy.And other advantages,the addition of a return lane after the braking lane,to make up for the shortcomings of downhill slope emergency escape ramp rescue and difficult obstacles,greatly improving the efficiency of the use of the truck escape ramp.This type of safety lane is being tested in Gansu Province and is still in its infancy.Therefore,in view of its own advantages and practical engineering value,this article studies from three aspects of the setting conditions of parallel truck escape ramps,the design of technical parameters,and the safety evaluation model.This article analyzes and explains the meaning,characteristics,setting conditions,setting principles,and setting distance of parallel truck escape ramps,and presents an analysis flowchart of the necessity of setting up parallel truck escape ramps in mountainous highways and the method of selecting the location on construction and operation highways.Through the establishment of models and theoretical analysis methods,the horizontal,vertical,and horizontal geometric design indicators of the parallel truck escape ramps are studied,and the recommended values of each index are given;The analysis of the application results gives the material types,laying methods and thicknesses of each structural layer of the brake lanes,and the drainage facilities,protective facilities,traffic signs,sight guidance facilities,and monitoring lighting facilities are studied in detail;combined with the management experience of operating highway truck escape ramps,an accident rescue work flow chart and rescue precautions for parallel emergency escape ramps are proposed,and it is suggested that the maintenance department should do the daily maintenance of the emergency escape ramps and the management of the trucks along the way.Based on the AHP-TOPSIS method,establish a safety evaluation model for the parallel truck escape ramps and rely on the national highway G30(Yongshan Expressway)and other expressways of the three parallel truck escape ramps specific design to applicate the safety model,and propose measures to improve its safety.