The Capacity of Urban Expressway Interchange

The traffic flow parameters of the basic segment, diverging and converging section, weaving section, and directional, semi-directional and loop ramp of these three interchanges were collected by field experiment. The simulation model of typical vehicle desired speed, deceleration and acceleration, and lane changing model on converging and diverging section were calibrated and validated with field collected datum within VISSIM software. The speed — flow curves of different segments of the interchange were determined by simulation experiments. And these curves can be used to obtain the capacity of whole of interchange and different segments of the interchange. Density was regarded as classification index of level of service and flow-density curves, which represents the operating conditions in interchange, was developed through simulation datum. And through these curves level of service of the interchange were discussed. Finally, the capacity and level of service of diverging section, converging section, weaving section and all kinds of typical ramps and whole of interchange are provided.