Aiming at the research on the stopping sight distance of the highway, on the basis of calculating the stopping sight distance in the current specification, the actual braking process of the car is divided into three stages: the driver's reaction stage, the braking force rising stage and the continuous braking stage. The calculation model of the complete braking stage is analyzed by MATLAB, and then the calculation model of the stopping sight distance of the ESC system is proposed. Considering the ambiguity of the operating speed, the fuzzy reliability theory is introduced to establish the function of the fuzzy reliability of the stopping sight distance. Using the Gaussian fuzzy number and the center point method, the reliability index and failure probability of the stopping sight distance are obtained, and the safety of the stopping sight distance is evaluated. According to the "Uniform Standard for Reliability Design of Highway Engineering Structures", the traditional reliability calculation method and the fuzzy reliability calculation method are used to calculate the stopping sight distance value that meets the corresponding reliability index of the highway safety level. The calculated value of the system stopping sight distance model is used as a reference, and the reliability index and failure probability of the two reliability calculation methods are calculated. The calculation results show that: compared with the traditional reliability calculation method, the fuzzy reliability calculation method calculates the stopping sight distance value with higher reliability index, lower failure probability and higher calculation accuracy. Implementing the road design based on the stopping sight distance value calculated by the fuzzy reliability theory can improve the road safety.

Considering the randomness and fuzziness of highway route design parameters, based on the reliability theory and triangular fuzzy numbers, the fuzzy variables are transformed into random variables. Three new fuzzy reliability calculation methods of highway alignment are derived, namely, the equivalent density function method, the information entropy method, and the general density function method. The proposed calculation methods are applied to the reliability analysis of highway horizontal curve design. The results show that if the fuzzy variables are symmetric fuzzy numbers, the equivalent mean values obtained by the three methods are equal. If the fuzzy variables are asymmetric fuzzy numbers, the equivalent mean values and equivalent standard deviations of the three methods are different. Compared with the traditional reliability calculation method, the values obtained by the proposed method have a large reliability index, small failure probability, and high calculation accuracy. Compared with the other two methods, the general density function method has the fastest convergence and higher accuracy. The general density function method is then applied to the calculation of highway circular curve radius, under the condition of a superelevation failure rate of 5%, to generate the recommended values of the safety and reliability index.