A safe headway to the lead vehicle is important to reduce conflicts with merging vehicles from highway on-ramps. Previous research has outlined the advantage of gap metering strategies to yield sufficient space to merging vehicles and improve highway capacity during peak hours. However, prevailing gap metering systems fail to indicate the minimum required gap and leave it to the drivers’ judgment to adjust their headway. This paper proposes a new Active Gap Metering (AGM) signalization that helps outer lane drivers to adjust their headway to the lead vehicle when approaching highway ramps with incoming vehicles. This AGM signalization represents a combination of pavement markings and an innovative Variable Message Sign (VMS). The AGM system was tested alone and in combination with additional variable speed limits (VSL) in distinct environments of the Doha Expressway in the State of Qatar using a driving simulator. The driving behavior of 64 drivers was analyzed using repeated-measures ANOVA. The results showed that the AGM effectively influenced the drivers’ behavior on the right stream lane. Drivers did gradually increase the distance to the lead vehicle, which resulted in optimal headways to merging on-ramp vehicles. Most importantly, the minimum time-to-collision (TTC_min) to the merging vehicle was increased by an additional 1–1.5 s as compared to no treatment. The proposed AGM signalization can, therefore, be considered by policymakers to influence drivers’ headways at critical merging sections.

通往领先车辆的安全行进对减少与高速公路匝道合并车辆的冲突至关重要。先前的研究概述了间隙计量策略的优势，即在高峰时段产生足够的空间来合并车辆并提高高速公路通行能力。但是，现行的间隙计量系统无法指示最小的间隙要求，并由驾驶员自行判断以调整前进的距离。本文提出了一种新的主​​动间隙计测（AGM）信号，该信号可帮助外车道驾驶员在驶入车辆驶入高速公路坡道时调整其向领先车辆的行驶距离。该AGM信号表示路面标记和创新的可变消息标志（VMS）的组合。AGM系统已单独测试，并与其他变速限速（VSL）结合在卡塔尔州多哈高速公路的不同环境中使用驾驶模拟器进行了测试。使用重复测量方差分析分析了64位驾驶员的驾驶行为。结果表明，AGM有效地影响了驾驶员在右流车道上的行为。驾驶员确实逐渐增加了与领先车辆的距离，从而使合并匝道车辆的行驶距离达到了最佳。最重要的是，最短碰撞时间（TTC 驾驶员确实逐渐增加了与领先车辆的距离，从而使合并匝道车辆的行驶距离达到了最佳。最重要的是，最短碰撞时间（TTC 驾驶员确实逐渐增加了与领先车辆的距离，从而使合并匝道车辆的行驶距离达到了最佳。最重要的是，最短碰撞时间（TTC与不进行处理相比，合并车的_min）增加了1-1.5 s。因此，决策者可以考虑提议的AGM信号灯，以影响关键合并区驾驶员的前进。