Abstract: The expressway system is an important part of the main framework of urban road network. Whether its main channel can be brought into full play is often subject to the traffic capacity of bottleneck sections. Under the condition of lane-reduction in expressway tunnel section, starting with the analysis of the road conditions of the tunnel section, the temporal and spatial distribution characteristics of traffic flow were extracted from the traffic detection big data. Then, the Greenshields traffic flow model and lane calibration model were selected. The traffic capacity difference of each lane between the tunnel section and the adjacent ordinary section was compared, the expected capacity and operating capacity of each lane in the tunnel section was evaluated. The traffic capacity difference between the two modes of gradual narrowing and signal controlling were compared. A signal control improvement scheme considering traffic volume maximization and right of way fairness was proposed. It is verified that lane capacity decays from inside to outside; the operating capacity is lower than the designed capacity. The proposed signal control improvement scheme can increase the traffic capacity by 3.4%.

Key words: traffic and transportation engineering; road capacity; Greenshields model; tunnel section; urban expressway

摘要： 快速路系统是城市路网主骨架的重要构成部分，其主通道作用能否充分发挥，常受制于瓶颈路段通行能力。在快速路隧道路段车道缩减情形下，分析隧道路段的道路条件，从交通检测大数据提取交通流时空分布特征，选用Greenshelds交通流模型，分车道标定模型。对比隧道路段与紧邻的普通路段各车道通行能力差别，评估隧道路段车道期望通行能力、运行通行能力；比较渐变缩窄与信号控制两种模式缩减车道的通行能力差异，提出兼顾通行量最大化与路权公平的信号控制改善方案。验证了：车道通行能力自内向外衰减；运行通行能力比设计通行能力低；提出的信号控制改善方案可提高通行能力3.4%。

关键词: 交通运输工程；道路通行能力；Greenshelds模型；隧道路段；城市快速路