Research on Longitudinal Slope of Highway Based on Control by Flow Path Length

Flow path on the highway is longer, driving exits the more dangerous. Based on the mechanical theory, the calculation models of the flow path length in different sections were built by FDM and multiple linear regression method. The flow path length of different section and different longitudinal slope was studied. The results show that: in addition to straight line and circle curve, when the number of lane is more than 4 and longitudinal slope is greater than 4%, the flow path length at other sections almost exceeded the prescribed value. Made the flow path length as control index, the amendment value on the maximum longitudinal slope of highway is proposed.