Estimating Traffic Flow Models for Urban Expressway Based on Measurement Data

The existing traffic flow models,including fundamental diagram and three-phase traffic theory,are conducted based on the highway traffic flow data.Because there exist significant differences between the highway and urban expressway traffic characteristics,the traffic flow models which developed based on highway traffic flow data,are not always suitable for the traffic flow conditions of the urban expressway.The measurement data of the urban expressway is used in this paper to develop the traffic flow models.The traffic flow models of speed-occupancy,traffic flow-occupancy,and speed-traffic flow are proposed using the linear regression analysis.The least square method is adopted to estimate the model parameters,and the significance of model fitting and parameters is tested by F-and T-test.Some key issues are investigated,such as the traffic states splitting and impacts between traffic flow parameters.The results demonstrate that the developed traffic flow models are feasible for the short-term traffic flow prediction and the traffic flow identification.