The Travelling Laws Of Free Vechicles And The Influence Of Cross Section Sizes Of Highways On Their Free-flow Speeds

The crossing section design is one of the most important task in road geometric design. The technical standard of highway engineering of our country take the design speed as the main design parameter, but in fact the vehicle's real speed is higher than the design speed, it will cause the safety problem. Now the operating speed will take place the design speed as the main design parameter. Because driver's custom .traffic composing and the vehicle's character are different between our country and the other countries , the other country's standard and parameter are fit for ours.So, at the basis of summing up the literatures about cross section, acceleration and deceleration, this paper discussed the vehicles characteristics and the influence of cross section elements on their speed in free-flow with the systems analysis as the guidanceWith the data collected from experiments and roads, this paper sum up the influence of cross section elements on the vehicles in free-flow, bring forward the operating speed in many cross section conditions, and finally have some suggestion to the crossing section design in our country.In the vehicles normal operating conditions, staring from rest and ending to the rest always will happen. Based on the GPS data collected from the expressway, this paper analyzed the acceleration characteristics and deceleration characteristics combining with the classical kinematics equations, establish the model of acceleration and deceleration...