互通式立交匝道连续分流点最小间距研究

Minimum Spacing between Successive Exits Terminals in Interchange Ramps

匝道连续分流点间距是互通式立交规划设计的重点,对交通运行有重要影响。首先分析了交通量、运行速度、交通标志布置对匝道连续分流点最小间距的影响;其次,结合现场调研,分析匝道连续分流区车辆换道行为和不同换道型式下最小间距组成,运用交通冲突技术对不同车道变换型式进行交通安全评价;基于驾驶员行为理论和可接受间隙理论,从交通标志识认距离、车辆换道所需的最小安全距离、减速车道长度等3方面,建立互通式立交匝道连续分流点最小间距计算模型;最后通过实例验证了最小间距计算模型的可靠性,可以为山地城市互通式立交规划设计提供技术参考。

The minimum spacing between successive exit terminals is the core of plan and design of interchange ramps and it is important for traffic operation. The effects of traffic volume, operating velocity, layout of traffic sign on minimum spacing were analyzed∽ And lane-change behaviors in ramp successive exit area and the composition of minimum spacing in different types of lane-change modes were studied based on the field investigation. Then, the traffic safety evaluation on different types of lane-change modes was carried out with the traffic conflict technique. According to traffic sign recognition distance, the required minimum safe distance of lane-change and the length of deceleration lane, the model of minimum spacing be- tween successive exit terminals in interchange ramps was established, on the basis of drivers＇ behavior theory and the gap acceptance theory. And a case study was conducted to verify the reliability of the minimum spacing model. This model pro- vides technical reference for interchange planning and designing in mountainous city.