Research On Left Turning Driving Behaviors From Branch At UN-Signalized Intersection

Intersection is the key node of urban roads, especially security issues and traffic efficiency at un-signalized road intersections have been concerned by the transport researchers. And drivers’ factors are closely related to road traffic safety, besides the vehicle, road and environment factors influencing the traffic safety at the same time. Now few studies research on left turning driving behavior from branch as a whole at un-signalized intersection.Accordingly, data acquisition by video at current typical road un-signalized intersection in Nanjing, and the crossing time of vehicles from branches to cross the main road is regarded as the evaluation index, the distribution differences of crossing time under different influential factors are analyzed using ANOVA methods, then exponential distribution model is selected as the optimal model by comparison with different model, thus obtaining the expectation model of crossing time of left turning vehicles from branch, indirectly indicating operation characteristics of left turning driving behavior of vehicles from branch at un-signalized intersection. And the security of left vehicle from branch is analyzed through the model, and obtaining:under bad weather conditions, parking on the main road lane and the increment of traffic flow rate and speed Sel from east approach leading to its security reduce. And the whole crossing time of left vehicles from branch could be regarded as the actual delay. Then control delay calculated by HCM, compared to the actual delay obtained statistically and expected delay deduced, obtaining:expectation model of the whole crossing time to consider the combined effect of various factors, the error between expected delays and actual delays is relatively small, indicating that this refined model is better than calculation model in HCM manual.By two logistic regression model proposed, deeply analyzing the influential factors and their importance degree on parking behavior on main road lane and abnormal behavior of track selection from established model. And an conclusion drawn:the increment of traffic flows rate and speeds Sel from east approach as well as traffic flows rate from west approach, branch vehicles located latter position on the edge line of lane, result in tending to choose the parking behavior on the main road; the increment of traffic flows rate from east approach and west approach, branch vehicles parking on the main road, result in tending to choose abnormal tracks to cross the intersection. It’s significant to provide the appropriate support for management and safety design, safety training and policy formulation of driver-related for un-signalized intersection, the detailed suggestions are provided to exhibit the practical value of this paper.