In order to improve the smoothness of traffic flow on bidirectional two-lane highways, an analytical method is proposed to optimize the minimum spacing of the signalized intersections. The minimum signal spacing is de...In order to improve the smoothness of traffic flow on bidirectional two-lane highways, an analytical method is proposed to optimize the minimum spacing of the signalized intersections. The minimum signal spacing is determined by two parts, including the necessary distance for stabilizing the traffic flow after it passes through the signalized intersections and the length of the upstream functional area of intersection. For the former, based on the platoon dispersion theory, the stable distance determination problem of traffic flow is studied and a model of dispersion degrees varying with the distance from the upstream intersection is presented, in which the time headway is intended to yield the shifted negative exponential distribution. The parameters of the model for medal and collector highways are estimated respectively based on the field data. Then, the section at which the slope of dispersion degree curve equals -0.1 is regarded as the beginning of the dispersion stable state. The length of the intersection upstream functional area is determined by three parts, including the distance traveled during perception-reaction time, the distance traveled while a driver decelerates to a stop, and the queue storage length. Based on the above procedures, the minimum signal spacing of each highway category is proposed.展开更多
A vehicle conflict detection and resolution method is proposed based on the concept of vehicle infrastructure integration （VII） system to prevent vehicle accident beforehand at blind cross- ing. After analyzing traf...A vehicle conflict detection and resolution method is proposed based on the concept of vehicle infrastructure integration （VII） system to prevent vehicle accident beforehand at blind cross- ing. After analyzing traffic conflict characteristics and vehicle collision scenarios at intersection, a vehicle dynamics model and an inter-vehicle communication method are discussed. In the inter-vehi- cle communication environment, the relative relationship between two encountered vehicles are de- signed. Then vehicle conflict detection and resolution algorithms under two conflict scenarios are put forward to represent the conflict-free movements of vehicles with adjusting vehicle velocity at cross- ing. Finally, simulation studies are carried out and the results prove that the proposed algorithms are effective for vehicle conflict resolution at blind crossing.展开更多
基金The National Natural Science Foundation of China(No.5120810051308192)
文摘In order to improve the smoothness of traffic flow on bidirectional two-lane highways, an analytical method is proposed to optimize the minimum spacing of the signalized intersections. The minimum signal spacing is determined by two parts, including the necessary distance for stabilizing the traffic flow after it passes through the signalized intersections and the length of the upstream functional area of intersection. For the former, based on the platoon dispersion theory, the stable distance determination problem of traffic flow is studied and a model of dispersion degrees varying with the distance from the upstream intersection is presented, in which the time headway is intended to yield the shifted negative exponential distribution. The parameters of the model for medal and collector highways are estimated respectively based on the field data. Then, the section at which the slope of dispersion degree curve equals -0.1 is regarded as the beginning of the dispersion stable state. The length of the intersection upstream functional area is determined by three parts, including the distance traveled during perception-reaction time, the distance traveled while a driver decelerates to a stop, and the queue storage length. Based on the above procedures, the minimum signal spacing of each highway category is proposed.
基金Supported by the National High Technology Research and Development Program of China("863"Program) (2011AA1104032011AA110402)
文摘A vehicle conflict detection and resolution method is proposed based on the concept of vehicle infrastructure integration （VII） system to prevent vehicle accident beforehand at blind cross- ing. After analyzing traffic conflict characteristics and vehicle collision scenarios at intersection, a vehicle dynamics model and an inter-vehicle communication method are discussed. In the inter-vehi- cle communication environment, the relative relationship between two encountered vehicles are de- signed. Then vehicle conflict detection and resolution algorithms under two conflict scenarios are put forward to represent the conflict-free movements of vehicles with adjusting vehicle velocity at cross- ing. Finally, simulation studies are carried out and the results prove that the proposed algorithms are effective for vehicle conflict resolution at blind crossing.
