道路入口匝道连接处通行能力计算模型

Calculating model for the capacity of the junction at on-ramps

结合入口匝道的特点,给出了入口匝道连接处交通流参数之间关系的理论模型以及入口匝道的通行能力计算模型.将连接处参数之间的关系模型整理成汇入率、上游外侧车道流量和密度之间的关系,并且利用实测数据对关系模型进行标定.与美国道路通行能力手册(HCM2000)的经验公式和算例进行了比较.结果表明:流量与汇入率呈指数函数关系;流量-密度呈线性函数关系,并与美国经验公式一致.

Given are theoretical model for the relationship among traffic flow parameters of the junction at on-ramps and calculation model for the capacity of on-ramps, based on the characteristics of on- ramps. The relationship among the parameters were turned into the relationship among merging rate, the Lane 1 flow entering the junction and the junction density, and this relationship model was calibrated by the measured data on the spot. Calibrated results were compared to the empirical formula in Highway Capacity Manual 2000（USA） and practical examples. The results indicate that the relationship between the flow and merging rate is exponential, and the flow-density relationship does linear, being agreeable with the empirical formula from America.