Studies On Bicycle Flow Modeling Based On Cellular Automaton

As the continuous deterioration of traffic problem worldwide, how to regulate and manage the traffic system and how to relocate resources have been attracting people's attention. Intelligent Transportation System is an effective way to regulate, manage and control traffic system, in which modeling and simulation play significant roles. Bicycle flow, as an important part of traffic flow, is flexible and human-driven, having its unique characteristics. It interacts with other traffic participants and affects the whole traffic system. Plenty of work has been done on bicycle flow modeling these years while more remains to be done. A comprehensive model of bicycle flow has not been reached.Based on the analysis of characteristics of bicycle flow, two microscopic models and a mesoscopic model were developed in this paper. The main contributions of this paper were concluded as follows:(1) The existed microscopic bicycle flow model was improved based on the characteristics of bicycle flow. Through analysis of relationship between speed and density, the unnegligible affect of desired speed was concluded. The existed bicycle flow model was improved by being implemented with desired speed. Simulation results demonstrated the accuracy of the model.(2) To increase the expansibility of the microscopic model, a new model was proposed - Extended Cellular Automaton Model: It features two characteristics -Layers and Matrixes. It updated through calculation of matrixes. Different sorts of factors influencing bicycle behaviors were described in different layers. Acceptable distances were considered to manage the conflicts of traffic participants at intersections. Simulation results showed consistent characteristics with the real data. Qualitative experiments were conducted to validate the effects of navigation, traffic light. Conflicts at intersection were also simulated.(3) A mesoscopic model, Cell-Stream Model was proposed. Cell was used to depict bicycles with the same characteristics while Stream was used to depict bicycles with the same destination at intersections. This model was able to reflect the input speed-density relationship. It is simple and fast, suitable to be adopted in large-scaled simulation. This mesoscopic model was individual-based, therefore can be possibly used to develop hybrid models with microscopic models.