两车道公路超车视距对行车速度的影响

本文采用瑞典VTI交通模拟模型研究两车道公路上超车视距对行车速度的影响,提出了部分结果.结果表明视距和超车密度(超车次/公里·小时)、超车密度和行车速度有十分密切的关系.研究结果可用于评价两车道公路的服务水平及检验和建立二车道公路的几何设计标准.最后建议超车视距应在两车道公路规划和设计中作为一条基本的考虑因素.超车道、爬坡车道和铺砌路肩由于能提供良好视距,因此都是新建和改建道路时应考虑的方案.

The Effect of Overtaking Sight Distance on Journey Speed in Two Lane Rural Roads

This paper presents some findings of a study of the effect of overtaking sight distance on journey speed in two lane rural roads by means of Swedish VTI Traffic Simulation Model.The findings reveal that there are strong relationships between sight distance and overtaking concentration, and between overtaking concentration and journey speed. The implication of the findings is the provision of the level of service evaluation and the test and determination of the criteria of geometric design for two lane rural roads. This paper concludes with a recommendation that the critera of overtaking sight distance is an essential element in two lane rural road planning and design. Overtaking lanes, climbing lanes and paved shouders are all viable alternatives to new and improved roads since they can provide better sight distance.