Study On The Operation Speed Of Traffic Safety In Mountainous Area Highway

Some longitudinal routes frequently appear on steep mountain area. Because of different dynamical performance of vehicles, the speed of different vehicles will vary greatly.The speed of large vehicles is lower than small vehicles’, which resulting in overtaking frequently betweent different vehicles, then traffic accidents happened. In order to keep running smoothly, vehicles must brake coercively on steep mountain area.It is very easily lead to brake failure appearance,then traffic safety is affected seriously. So it makes profoundly sense to enhance traffic safety on steep mountain area,according to studying traffic safety on longitudinal routes.Based on the analysis of case-related research at home and abroad, and Combined with field research, studying traffic safety through non-accident rate method on longitudinal routes. For uphill, according to VISSIM simulation test to research on traffic safety about slope factors, slope length factors, traffic flow factors, carts mixed rates factors and so on, then four parameters affect s on traffic safety will be got. Last, it is necessary to propose improvement measures through the analysis.For downhill, Multiple nonlinear regression method has been chosen to establishe two representative vehicles speed prediction model adout Slope, slope length and radius, according to analysis two representative of the vehicles driving characteristics on longitudinal routes. Then calculates the estimated value of the operating speed, and grade the downhill sections according to the degree of danger. Make sure the hazards of the routes through the dangerous grade, which provide data support for traffic safety research. It is necessary to propose improvement measures through the analysis.It makes sense to optimize the future design of longitudinal routes according to thesis conclusion. At the same time, It is of great guiding value to provide safety improvement measures on longitudinal routes.