Empirical estimation of the width of highway roadside clear zone

Abstract

In order to provide theoretical gist and support, this paper studied calculation method of roadside clear zone's width. Firstly, main influencing factors of highway roadside clear zone's width are analyzed, including shoulder width, degree of side slope, braking reaction time, state of vehicle running on roadside (departure angle and speed). Calculation method is proposed based on classical physics theory, and the accuracy of the method is verified by the simulation test of PC-Crash software. Lastly, suggestion values of roadside clear zone's width are given. The results of this paper are expected to provide design and decision-making reference for highway designers and managers, and provide theoretical support for highway design standards and specifications, as well as revision for safety evaluation guidelines of safety evaluation guidelines.