Safety Research On Trunk Roads With Design Of Motor Vehicle Access

With the rapid development of the city, the increasing automobile holding quantities has brought about the serious traffic problems. As the core of the urban road system, the main road connects not only the inner road of the city, but also the suburban road. Because of its special function positioning, the entrance and exit area of motor vehicle will inevitably affect the traffic efficiency and traffic safety, which often lead to traffic congestion and traffic accidents. The overseas literatures are abounded about the layout structure and traffic organization of the entrance and exit area, comparatively, the safety researches for the design of entrance and exit area on specific trunk roads has not attracted enough attention.In view of this, this paper firstly analyzes the traffic flow characteristics of the motor vehicle entrance and exit function area of the main road, and then launches traffic safety researches on the main canal entrance and exit area based on the traffic conflict technique. By comparing the measurement indices of severity for traffic conflict, and according to the difficulty level of traffic data collection, PET is selected as the index of traffic conflict. Through the analysis of traffic conflict data, it can be divided into latent conflict, slight conflict and serious conflict, and it discusses the mechanism of the conflict happening in the entrance and exit function area. Then the PET value and traffic conflict severity are defined as the dependent variable of the equation, and the multivariate linear regression model and the Ordered Logit Model are established respectively, and the significant factors which influence the traffic safety of the entrance and exit area are explored.The results show that the PET value of traffic conflict between motor vehicles and non-motor vehicles is generally higher than that between motor vehicles and motor vehicles. The length of entrance and exit area passage, traffic sight are the safety variables, which alleviate the severity of traffic conflict. The speed difference and the secondary conflict between motor vehicles and motor vehicles and the confluence conflict between motor vehicles and non-motor vehicles aggravate the severity of the conflict, which are the risky factors of the traffic safety of the entrance and exit area. And then, the causes of each significant variable and the influencing mechanism of the safety of the entrance and exit area are analyzed and discussed.At the end of this paper, it puts forward the geometric design method of the entrances and exits of in the main road of the motor vehicles, which is affected by the length of the entrances and exits channel, the turning radius of the entrances and exits corridor, the acceleration and deceleration lane and the traffic line of sight as well as the sign plate setting, so as to improve the traffic safety service level and eliminate security hazards from the roots can provide theoretical references and design basis for the geometric design and traffic management in urban main road of the motor vehicles’ entrance and exit area.