普通公路车速分布特性的回归分析

采用多元线性回归的方法,分别建立了平均车速、15%位车速、85%位车速与车道数、限速值、车道位置、车型、道路饱和度、大型车比例等6个因素之间的回归模型.然后,采用Logistic回归的方法,建立了车速选择的回归模型.分析结果表明:对于双向六车道普通公路,依据15%位车速,对超车道进行最低车速限制;依据85%位车速,对最高车速实施可变限速、分车道限速和分车型限速.外侧车道上的大型车在饱和度较高的情况下,容易选择低速行驶;双向两车道或四车道公路上的小型车在饱和度较低的情况下,容易选择高速行驶.根据车辆选择高速行驶的概率,设置不同的限速设施.利用这2个回归模型可以计算出特定道路条件下的15%位车速、85%位车速以及车辆选择高速行驶和低速行驶的概率,为普通公路在限速及限速设施选择方面提供依据.

Regression analysis on speed distribution characteristics of ordinary road

The regression models between the average speed,15th percentile speed,85th percentile speed and 6 factors,the number of the lanes,the value of the speed limit,the position of the lanes,the vehicle type,the road saturation and the proportion of the large vehicle,are established by the multiple linear regression,respectively.Then,the speed selection model is built by the Logistic regression.The analysis results show that for the two-way six lanes,the minimum speed limit of the passing lane can be controlled according to the 15th percentile speed,and the maximum speed limit can adopt the variable speed limit,the speed limit for different lanes and the speed limit by types of vehicles according to the 85th percentile speed.The large vehicles in the kerb lane often select low speed driving when the saturation is high,while the small vehicles in the two-way two(or four) lanes often select high speed driving when the saturation is low.Different speed limit facilities are set according to the probability of selecting high speed driving.These two regression models can be used to figure out the 15th percentile speed,the 85th percentile speed and the probability of selecting low or high speed driving under specific road conditions,providing a basis in choosing the speed limits and the corresponding facilities for ordinary roads.