高速公路封道施工路段交通流特性及通行能力分析——以杭州湾大桥内侧两条车道封道情形为例

基于交通流实测数据,针对三车道高速公路杭州湾大桥路段内侧两条车道因施工而封闭时的情形,建立元胞自动机交通流模型.根据公路养护安全作业规程和车辆行驶特点,细致划分了施工路段各区域,采用不同的换道规则来模拟不同区域中车辆的换道行为,区分车型和司机性格差异,模拟结果与实测数据吻合良好,验证了模型的有效性.通过数值模拟,研究发现封道时流量和速度随着进车率增加均有不同程度的下降,并且流量还会因施工区域长度的增加而下降.此外,通过分析封道时的道路服务水平评价指标与交通流特征值之间的关系,得出在三级服务水平以上时,道路通行能力能得到基本的保证,以此推荐了极限流量值,可为高速公路封道时的交通管理提供理论依据.

Analysis on traffic flow characteristics and capacity for the highway with lanes closure by construction: With case study of solution for Hangzhou Bay Bridge

Based on the collected data of traffic flow, a three-lane cellular automata traffic model is established for monitoring the highway in Hangzhou Bay Bridge section, whose two lanes of the inner side are closed due to mock construction. The construction areas are classified strictly according to the Safety Work Rules for Highway Maintenance and vehicles’ driving characteristics. Different lane-changing rules are proposed to simulate the lane-changing behaviors of vehicles driving in different areas, in which vehicles’ type and drivers’ character are distinguished. The simulation results are in good agreement with the measured data, which verifies the validity of the model. Through numerical simulation, it is found that the traffic flow and vehicles’ speed decrease to varying extent with the growing number of merging vehicles when two lanes are closed, and the traffic flow decreases with the increase of the construction area’s length. In addition, by analyzing the relationship between the road service level evaluation index and the traffic flow characteristics during the road closure, the result is obtained which suggests that the essential traffic capacity can be ensured when the service level is above level three, and thus the specific limit flow is recommended. The study result is expected to provide the theoretical basis for the highway traffic management during the road closure period.