Reducing road width can not only save land, but it can also increase traffic safety. However, the traffic flow mechanism due to lane narrowing is not clear and car-following behaviour may also change greatly in this condition. To investigate the influence of lane narrowing, traffic flow data and vehicle trajectory data were collected at a four-lane road section with ultra-narrow lanes during off-peak hours. Statistical analysis of the data revealed that the speed difference between vehicles on an ultra-narrow lane is significantly smaller in unsaturated traffic conditions and the free-flow speed is obviously limited by the lane width, both of which indicate safer traffic flow. Deeper analysis of space speeds and longitudinal gap distances showed that there is a significant correlation between the following distance and the longitudinal gap distance in the adjacent lane, which reveals the special phenomenon that vehicles in different lanes follow the same header vehicle in narrow lanes. In addition, it was also found that the greatest speed difference between the vehicle groups was generally less than 3.5 km/h when staggering occurred. This study provides a theoretical basis for research into car-following theory and decision making while driving in narrow-lane conditions.

中文翻译：

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超窄车道车流速度分布稳定性及机理

减少道路宽度不仅可以节省土地，还可以提高行车安全。然而，由于车道变窄引起的交通流机制尚不清楚，跟车行为也可能在这种情况下发生很大变化。为了研究车道变窄的影响，在非高峰时段在超窄车道的四车道路段收集交通流量数据和车辆轨迹数据。对数据进行统计分析发现，在非饱和路况下，超窄车道上车速差异明显较小，畅通车速明显受车道宽度限制，表明车流更安全。对空间速度和纵向间隙距离的深入分析表明，相邻车道的跟车距离与纵向间隙距离之间存在显着相关性，揭示了不同车道的车辆在狭窄车道上跟随同一头车的特殊现象。此外还发现，发生踉跄时，车组间的最大速度差一般小于3.5km/h。本研究为狭窄车道条件下车辆跟驰理论与决策研究提供了理论基础。还发现，当发生摇摆时，车辆组之间的最大速度差异通常小于 3.5 公里/小时。本研究为狭窄车道条件下车辆跟驰理论与决策研究提供了理论基础。还发现，当发生摇摆时，车辆组之间的最大速度差异通常小于 3.5 公里/小时。本研究为狭窄车道条件下车辆跟驰理论与决策研究提供了理论基础。