Evaluating Skidding Risk of a Road Layout for All Types of Vehicles

Abstract

This paper represents an update to earlier research by the authors on a new method for analyzing the friction of road vehicles. With the third criterion of Lamm as a starting point, the new concept of “friction capital” was introduced in previous work as the performance limit of the road in terms of friction. This method was named the friction diagram method; its output is the friction diagram, which represents the percentage of friction capital that a vehicle uses traveling on a given road. During the design step, the friction diagram could be used to quantify the risk of skidding related to a given road layout. In this paper, the authors investigate the influence of vehicle type on the friction diagram, because it was observed that the type of vehicle used in analyzing a road segment affects the values of friction capital when the boundary conditions and the road geometry change. This finding led the authors to identify the vehicle to be used in detecting skidding risk. This vehicle has been named the “design critical vehicle.” Use of the design critical vehicle enables faster detection of the road sections with high skidding risk by using a single friction diagram and avoiding the need to perform the same analysis for various vehicles. Determining the design critical vehicle could be useful in the application of the friction diagram method both in designing roads and in checking existing roads.