A Study on Freeway Ramp Merging Phenomena in Congested Traffic Situation by Traffic Simulation Combined with Driving Simulator

This research studies freeway ramp merging phenomena under congested traffic situation via a Driving Simulator (DS). The main objectives of this study were to initially develop a traffic simulation, which evaluates the capacity of merging section relevant to the geometric design and the flow condition. Furthermore, to form a pilot system of the DS combined with the simulation, from which the driving behavior of freeway ramp merging vehicles can be observed. Based on extensive macroscopic and microscopic study, a behavioral model has been established. In addition and based on the behavioral model the Freeway Merging Capacity Simulation Program (FMCSP) is instituted for simulating the actual traffic conditions. Furthermore, a DS is developed and a pilot study has been performed, to detect the potential deficiencies of combined system of FMCSP and DS. Finally, the main experiment was performed to collect the required data for further study. Driving behavior data of 12 persons was collected while they were driving in the driving simulator and merging at the Ichinohashi merging section. In addition, two participants of DS experiments were asked to drive an instrumented car and perform the merge maneuver in the real driving environment. Driving behavior data of DS, instrumented car, and observed drivers were used to examine differences between simulator’s driver behavior and that in the virtual world. Results indicated that not only the FMCSP is capable of simulating actual traffic condition of congested freeway ramp merging process but also DS is a capable and promising substitution tool to study complicated freeway ramp merging phenomena.