The Approach Of Multiplexing For Bus Lanes And Fractal Collaboration Of Vehicles

On the premise of ensuring bus priority strategy, to make full use of bus lanes and in view of problems existed in the multiplexing technology of bus lanes, a novel approach of time division multiplexing for bus lanes ensuring the bus priority is researched.First of all, the concept of time division multiplexing for bus lanes is proposed. To meet the needs of accomplishing bus lanes multiplexed, a technical system of the method of time division multiplexing for bus lanes is established, in which the system of time division multiplexing for bus lanes, the Kalman filtering algorithm of the GPS/DR/RFID integration of positioning method, multiplexing rules and implementing conditions are described in detail.Secondly, the core of time division multiplexing for bus lanes is spatial and temporal control method, to control various types of vehicles to use bus lanes fully and orderly. To determine the time and space of using bus lanes by various types of vehicles dynamically, concepts of time slices and space slices are proposed. Space slices divided is based on length of links and location of buses. Based on division of space slices, time slices which are time of different types of vehicles on bus lanes are allocated to the corresponding vehicles. Then division result of time slices and space slices are changed into the control message to warn vehicles to borrow or return bus lanes through expressing time slices and space slices.Thirdly, there are several problems when bus lanes are multiplexed, such as some vehicles moving into bus lanes at the same time, vehicles that should returning bus lanes to ensure bus priority moving out bus lanes in time and so on. Because Vehicle Infrastructure Integration (VII) can give supportion to communication in vehicles’collaboration, and fractal theory can simplify vechicles’collaboration system by simple cells stacked and integrated and control the vehicles’ collaboration process by simple rules. In view of these problems, the paper introduces technology of VII and fractal theory to propose the method of vehicles’fractal collaboration supported by VII and use it into multiplexing bus lanes.Finally, selecting one of BRT lines (B1) in Hangzhou as simulation object, the method of time division multiplexing for bus lanes is tested by secondary development in PARAMICS. The paper analysises selection and optimization process of key parameters in the method of time division multiplexing for bus lanes, and compares the change of state roads before and after implementing the method of time division multiplexing for bus lanes.Finally the outcome of simulation verifies that in application range the optimized approach of multiplexing for bus lanes could not only ensure bus priority but also promote the higher traffic speed, the lower traffic density and the less average travelling time on the multiplexing link than before. The method of vehicles’ fractal collaboration can reduce returning time and buses delay on multiplexing link because of bus lanes multiplexed.