The Maximal GradeLine Limit Of Separate Section In Montane Highway

Highway alignment include horizontal alignment and vertical alignment, which is the highway's framework, it difficult modify even can't modify if it is designed. The emphasis of montane highway design is vertical alignment's design, there are usually two controls parameters: concessional maximal longitudinal and concessional maximal length of grade. The first parameter can be confirm according to the specification, then the second parameter can be calculated according to the concessional increment (downgrade) or decrease (upgrade) of speed. In this paper, the operation characteristics of car is applied to road alignment design, with analysis of vehicle tractive performance, braking performance of automobile and motive equation of vehicle in the road, put forward prepositional value of maximal length of grade, and experiment verify analysis's accuracy. Finally, select designed stretch and make the alignment's evaluation of it.