Abstract: According to the analysis of the measured data, the driving behavior features and traffic flow characteristics of the multi-road merging section in urban were obtained; by introducing the drivers' character parameter and the probability of lane changing considering the drivers' psychology, the cellular automaton (CA) of multi-road merging section in urban was established. Through the verification of JAVA numeral simulation and model, the traffic flow characteristic parameters for both types of speed- changing ramp, the direct type and the parallel type, were acquired. The results indicate that: the direct type is not conducive to the main line and ramp vehicles, and vehicles on the right ramp have severe interferences on the middle ramp; a too long parallel speed-changing ramp exacerbates the conflictions between the main and middle ramp, meanwhile, increases the effect of the middle ramp on the right ramp. In addition, the direct type increases the traffic congestion of the merging region, and by contrast, the length of parallel speed-changing ramp within a certain range can clearly improves traffic conditions of the merging region, but too long parallel speed-changing ramp leads to the counterproductive result.

Key words: traffic and transportation engineering, multi-road merging region road, speed-change lane, cellular automaton, traffic flow characteristics

摘要： 根据实测数据分析，得到了城市道路多路合流路段的驾驶行为特性和交通流特性；引入驾驶员性格参数和描述驾驶心理的选择换道概率，建立了城 市道路多路合流的元胞自动机模型 (Cellular Automaton，简称CA)；由JAVA数值模拟，模型验证后，得到了变速车道分别为直接式、平行式的多路合流 的交通流特征参数。研究表明：直接式不利于主线、多条匝道的车辆通行，右侧匝道车辆对中间匝道的干扰严重；过长的平行式变速车道，加重了主线与 中间匝道之间冲突，增大了中间匝道车辆对右侧匝道的影响。此外，直接式加重合流区的交通拥堵，相比之下，一定长度范围内的平行式变速车道对于合 流区的交通运行状况改善明显，但过长的平行式变速车道会适得其反。

关键词: 交通运输工程, 多路合流路段, 变速车道, 元胞自动机模型, 交通流特性