Study On Characteristics And Application Of Bicycle Traffic Flow

Mixed traffic is the main characteristic of urban traffic in developing country. It is also the sticking point of traffic problem and difficulty of traffic management, and that bicycle problem is especially prominence. Because of the existence of mixed traffic, operational order is disordered and traffic accident is frequent in our many cities. Existent traffic control system can not exert the function because of bicycle traffic. So, it is necessary to research on characteristic bicycle traffic flow, and then corresponding traffic management and control policy are established basing on it. It should put forward new thinking and method to resolve problem on mixed traffic in our country. Basing on this research groud and aim and supported by National Natural Science Foundation and GM Scientific Research, the macroscopical and group characteristic and the application of bicycle traffic flow are researched in this dissertation.In the first part of the dissertation, the existent inevitability, advantage and disadvantage and running situation of bicycle traffic are analyzed concretely. After concluding the research method and content about unit characteristic, group characteristic, signal timing, capacity and delay of bicycle traffic flow, research significance of the dissertation is discussed, and then the main research content in each chapter is respectively dissertated in detailed.In the second part of the dissertation, the main research content is bicycle traffic flow macroscopical characteristic. The author defined the definition of three based parameters: volume, velocity and density of bicycle traffic flow basing on motor vehicle traffic flow theory. Statistical characteristics of velocity, saturation and congestion density of bicycle traffic flow are research. And then general model of traffic flow and relation ship model between velocity and density are established. Basing on the survey data, the validation result shows that error between practical and theoretical value is under 8%. It can prove that the model is credible. As following, we can obtain other two relation ship models, one is volume and density, the other is velocity and volume. All research results illuminate that the bicycle have the similar traffic flow model with the motor vehicle.In the third part of the dissertation, the main research content is bicycle traffic flow characteristic based on group. Basing on the gap theory, interspace is introduced to define bicycle group at first, and then bicycle group is compartmentalized. Statistical characteristics of bicycle group at intersection and on road segment are researched respectively. The results show that the interspaces between bicycle group is decreasing and bicycle number including in the group is increasing with the increasing of bicycle volume. Additional, time length of bicycle group have the linear relationship with the bicycle number including in the group. But in a single cycle, the interspaces intend to increase with process of greed time. Finally, the compressed characteristic of bicycle traffic flow is researched according to hydromechanics, and then the stop wave model of bicycle traffic flow at intersection is established. The maximum queue length and the furthest queue location can be computed by applying this model.In the forth part of the dissertation, the main research content is signal timing method including signal timing method for bicycle and right-turn motor vehicle at vehicle-bicycle mixed intersection. Signal timing method for bicycle includes setting excluded phase and overlap phase. Overlap phase includes confirming forward close time of straight bicycle and left-turn bicycle under different timing plan, and that excluded phase includes demarcating critical value of choosing key flow and computing timing parameters. The signal timing method for right-turn motor vehicle includes setting overlap phase method basing on the characteristic of bicycle group. The confict between the right-turn vehicle and through bicycle decreased greatly after using the time method and the safrty and operational efficiency at intersection is advanced.In the fifth part of the dissertation, the main research content is operational effect at vehicle-bicycle mixed intersection. Operational effect is estimated from two points of view after defining the definition of it: one is traffic efficiency with the parameter of capacity; the other is level of service with the delay. All is make right-turn motor vehicle as the example. The capacity of right-turn motor vehicle includes two situations with and without signal control. The capacity with signal control is computed by conventional method which is the product of saturation and split. The capacity without signal control is computed by the corresponding model that is established basing on conflict theory. For the delay of right-turn motor vehicle, travel time is used to express the delay. The travel time model of right-turn motor vehicle is established basing on queue theory and gap theory as well as duality regression theory. The validation result from practice data shows that the model basing on queue theory and gap theory is suited to low bicycle volume, the whole validation result of duality regression model is better and proved credible by F-test. At the end of this chapter, channelization method of left-turn bicycle is searched facing different light color basing on the characteristic of bicycle group. The channelization plan greatly decreases the delay of left-turn bicycle at intersection and conflict with other traffic flows, then general safety and operational effect is increased at intersection.The last part of the dissertation is conclusion. The author sums up the work through completing the dissertation and put forward research content and direction in the future.