Study on Traffic Capacity in the Expressway On-Ramp Junction under Circumstance of Traffic Accident

he vehicles of on-ramp junction need to import or separate rapidly, and they will generate disruption to the straight vehicles. The result is the influence to the traffic capacity of mainline and entrance ramp when the accident takes place on the convergence. This paper mainly studies the traffic capacity of entrance ramp and adjoining mainline when the accident happens inside and outside the convergence and corresponding different lanes. According to the types of expressway on-ramp junction, i.e. isolated ramp and non-isolated ramp, build the models of traffic capacity through analysis, and make use of VISSIM to simulate and verify them. The result proves reasonability of the models.