Abstract:  Ｒoad driving comfort is mainly affected by the pavement roughness． At present， there are three evaluation methods: subjective feeling，driving vibration and heart physiological changes of drivers and passengers． Due to different test objects，test methods and evaluation criteria，the accuracies of different methods for road driving comfort evaluation are different，and the evaluation results are also different． In order to improve the accuracy and objectivity of road driving comfort evaluation，a comprehensive evaluation method for road driving comfort using D-S ( Dempster-Shafer) evidence method for decision-making fusion of three evaluation methods was proposed to test the outdoor riding test results of 12 asphalt pavements with roughness changing from 1. 06 ～5. 53m/km． The research results show that the comprehensive evaluation system of driving comfort based on road roughness established by D-S evidence method can significantly reduce the uncertainty of each evaluation method，verify the validity of the model，and obtain the absolute threshold of road roughness with 3 kinds of comfort evaluation methods; the speed has an important influence on the proportion of uncertainty in the comprehensive evaluation system，which is in line with the actual situation． 

Key words:  IRI ( international roughness index), driving comfort, D-S evidence theory, decision fusion, comprehensive evaluation method