How to Evaluate the Road Consistency and Driving Comfort of a Newly-Built Freeway—A Case Study of the Wu-Liu Freeway in Guangxi

The freeway from Wuzhou to Liuzhou is a newly built branch in freeway network planning of Guangxi Zhuang Autonomous Region in China, providing more convenient access from Guangxi to the Pearl River Delta area. This study aims at improving safety performance and risk tolerance of this newly built freeway, in which a 40 km segment with complex geometric design was investigated. Driving simulation experiments were carried out based on a 3D model constructed with data of regional terrain and geometric design. 20 experienced drivers participated in the simulating experiments. Road consistency was evaluated through driver’s speed choice. Data on speed indicators were collected and analyzed, including average speed, standard speed deviation, speed variation coefficient, and speed difference between driving speed and design speed. Evaluation of driving comfort was obtained from driver’s heart rate, lateral acceleration and corresponding track deviation. The results show that the overall design of Wu-Liu freeway is of good quality and potential problems lie in S curve, curves with small radius, continuous curves with divergent radiuses and entrances to tunnels.