Connecting rural road design to automated vehicles: The concept of safe speed to overcome human errors

Abstract

The human-road-vehicle automated system is a challenge to overcome human errors. Several rural road crashes happen due to loss of friction, unlikely predictable by drivers. The friction diagram method (FDM) by the authors, described in previous papers, is able to evaluate the skidding risk taking into account vehicle, environmental, road factors. An important variable is the vehicle speed. According to the FDM, the speed corresponding to the maximum friction used can be computed. If all vehicles will travel at speeds lower than that, all other safety checks being verified, then the skidding risk can be reduced. Automated vehicles could travel at the safe speed predicted for each section, by acquiring all the necessary information directly from the road. The algorithm can be customized according to the particular vehicle, tires and road conditions. Additional remarks about the shift from traditional road design practice to the driving automation are also given.