关键词: 道路工程；客货分离；小客车专用匝道；超高值；超高分配模型

Abstract: In order to ensure the safe driving of vehicles on dedicated ramps and make full and effective use of road resources, the research on superelevation index of dedicated ramps was enriched to further improve road safety and service level. China’s regulations on the setting of circular curve superelevation and the setting of maximum superelevation value abroad were combined. The characteristics of passenger and freight separation highway was considered. The setting of the maximum superelevation value of passenger car and truck mixed roads recommended in the “Technical Standards of Highway Engineering” and “Guidelines for Design of Highway Grade-Separated Intersection” was referred to. Firstly, based on the factors such as passenger car driving safety, passenger comfort, environmental factors, construction and maintenance and traffic composition, it was proposed by using the mechanical analysis and calculation method that the maximum superelevation value of the dedicated ramp for passenger cars in non-ice and non-snow conditions should be 10%, and the maximum superelevation value in the snow and ice environment should be 8%. Secondly, the advantages and disadvantages of the point mass-rigid body calculation model (PMR) and the point mass-suspension calculation model (PMS) were analyzed and compared, and a superelevation calculation model suitable for passenger car ramp was proposed. Thirdly, based on the current situation of vehicles generally over-speeding on the special ramp for passenger cars, the AASHTO recommended superelevation and lateral force coefficient distribution model was optimized and improved from the perspective of safety, and a new superelevation and lateral force coefficient distribution model based on dangerous speed and suitable for the superelevation calculation of special ramp for passenger cars was proposed. The proposed model could not only ensure the lateral stability of low-speed or normal driving passenger cars, but also significantly improve the lateral stability and comfort of high-speed passenger cars. Finally, according to the new allocation model, the recommended setting values of superelevation for the dedicated ramps for passenger cars with different design speeds and radius was proposed.

Key words: highway engineering; passenger and freight separation; special ramp for passenger car; superelevation value; super-elevation distribution model