With the rapid development of economy in China,the number of automobiles is increasing constantly. The traditional manual toll collection (MTC)at freeway toll stations can no longer meet the current travel demand. Therefore,many provinces and cities are testing non-stop electronic toll collection (ETC).Simulated driving is used to study the key content of this paper:the mandatory signs at unattended freeway toll stations.A case study of Xihongmen-Nanqiao toll station at Beijing-Kaifeng freeway G45 is carried out in this study.5 types of common signs are used as study objects,and 1 6 types of sign combinations are developed.Through the following 7 types of data,including questionnaire data,average speed,standard deviation of acceleration,lateral displacement,absolute deviation of parking position, number of stops and the number of decelerations,each combination is evaluated based on the following 4 indices:visibility of the signs,convenience of picking up the toll-card,comfort of driving experience,and passing efficiency,then sorted them in order from good to bad.This study proposes the best and optimum design schemes of mandatory signs at unat-tended freeway toll stations for the first time.The study results provide theoretical foundation for relevant standards regu-lating the setting of mandatory signs at such stations.