Simulation of Freeway Weaving Areas

The operation of freeway weaving sections is characterized by intense lane-changing maneuvers and complex vehicle interactions that often create bottlenecks along freeway facilities. The CORSIM microscopic simulation model was applied to simulate the operation of eight realworld weaving sites in California under a wide range of operating conditions. The results indicate that CORSIM with default parameter values underpredicts the speeds in the weaving section by about 19% on average. Numerous simulation runs were made with different values of the model parameters. The following parameters were found to significantly affect the CORSIM results: ( a) car-following sensitivity factor, ( b) lane-changing aggressiveness factor, and ( c) percentage of freeway through vehicles that yield to merging traffic. The calibrated CORSIM model reasonably replicated observed traffic operations at all test sites. The predicted average speeds were within ±5 mph for most test sites. Good agreement between measured and predicted values was obtained for all the combinations of design characteristics and demand patterns.