Through an analysis on the expressway roadside environment from the real situation,a evaluation index system for roadside fault-tolerant environment was established to take following three aspects into consideration,that is,preventing vehicles from rushing out the laneway,avoiding the side tumbling or crash,and reducing accident severity.The Rough Set Theory and Gray Clustering Evaluation(RST-GCE) are used to establish an evaluation model for the roadside fault-tolerant environment.And then,the evaluation m...