双车道公路超车两难区域研究

基于超车行为分析,提出了双车道公路超车行为的两难区域概念,在该区域内超车车辆既无法完成超车动作又不能在避免与对向车辆相撞前安全避让。应用运动学理论建立了下游车队规模、车速、设计车速与两难区域范围以及安全超车视距之间的关系,发现与超越单车的视距要求相比,超越车队所需的安全视距较大,且随着设计车速、下游车队规模以及车速的增大而增大。并发现当流量或车速较大时,两难区域出现的概率较大,且因驾驶者错误估计引发交通事故的机会增多。最后给出了不同下游车队规模条件下安全超车的速度限制及视距要求,为制定安全行车策略以及道路安全管理提供了理论依据。

Dilemma Zone in Two-lane Highways

Based on passing behavior analysis,this paper introduced the concept of a dilemma zone(DZ) road segment,where a(vehicle) could not accomplish overtaking or avoid collision with the oncoming vehicle in two-lane highways.Kinematics theory is used to establish the relationship between downstream vehicles' speeds,number of vehicles,design speed and the length of DZ.It is found that compared with the case of one overtaking one,the safe distance for overtaking a platoon is larger,and will increase with the design speed,the size and speed of platoon increasing.It is also found that a high flow or velocity can increase the probabilities of DZ appearance and accident rate(resulted) from drivers' wrong estimations.Finally,the conditions of safe overtaking such as speed limit and visual scope are proposed for safety driving strategy and precautions.