主路不同流量条件下入口匝道通行能力研究

详细分析入口匝道和无信号控制交叉口交通行为的异同之处,借鉴无控制交叉口通行能力的诸多研究成果,运用接受间隙理论分析研究入口匝道通行能力,提出主路在低流量、中等流量和高流量时下车头时距分别服从移位负指数分布、2阶Erlang分布和3阶Erlang分布。考虑不同类型车辆汇入的临界间隙和跟车时距,建立主路不同流量条件下的入口匝道通行能力模型。求出相应条件下混合车流的入口匝道通行能力值,为高速公路及城市快速路的入口匝道控制以及系统控制提供基础信息。

On-Ramp Capacity under Different Flow Rate of Major Stream

The difference and similarity between on-ramp and unsignalized intersection on traffic behavior are analyzed in detail.By dint of the capacity achievements on unsignalized intersection,the scientific researches on on-ramp capacity are made with gap acceptance theory.The headway of major road accords with the displaced negative exponential distribution,2 order Erlang and 3 order Erlang distribution at low flow rates,moderate and high flow rates respectively.The capacity model of on-ramp is set up under the condition of the critical gap and following cars headway of the different vehicles.The relevant capacity value of on-ramp under mixed flow is calculated,which provides the basic information for the on-ramp metering and system controlling of the expressway.