机动车混合交通占有率-流量模型研究

Occupancy-Flow Model for Mixed Traffic Flow

在交通流基本参数模型中,密度参数难以直接获取,占有率-流量模型具有较强的实用价值。提出占有率分析单元概念,分析混合交通不同跟车组合下,大型车辆混入对分析单元中占有率参数的影响机理,综合分析单元出现概率,得出在占有率-流量模型中,原始占有率难以反映出大型车辆对交通流影响效应的结论,随后基于车头时距和大车率修正原始占有率,最终建立了机动车混合交通情况下的占有率-流量模型,并用北京快速路实测数据对模型进行了检验,证明占有率修正之后,占有率-流量模型更加精确。此模型等式两边都考虑了大型车辆的影响效应,具有更好的实际物理意义。

It is difficult to gain density parameter which can be used in traffic flow model, thus occupan-cy-flow model is more practical. The article proposed the conception of analytical unit of occupancy, ana-lyzed the influence mechanism of large vehicle based on different car-following combination considering the probability of analytical unit of occupancy, concluded that original occupancy could not reflect the im-pact of large vehicle on traffic flow and occupancy-flow model. Then the article modified occupancy based on vehicle headway and mixed rate of large vehicle, established occupancy-flow model in mixed traffic flow situation. Data collected from Beijing expressway showed the model in the article was effective and more meaningful.