Effects of Freeway Exit Ramp Types on Traffic Operations

摘要

Some proposals on classifying freeway exit ramps in China are put forward. Google Earth was used to identify the contributing factors on exit ramp classification by surveying more than 500 samples in China, USA, Japan, and Europe. The factors determined are configuration of deceleration lanes, number of deceleration lanes, lane changes in the mainline upstream and downstream segments, and number of ramp lanes. With the classification, four freeway exit ramp types are proposed. Furthermore, traffic operational performances of different types of freeway exit ramps were evaluated by studying traffic operational speeds (in the upstream segment, downstream segment, and exit ramp segment) and capacities by TSIS package and field observations. Thus, reasonable exit ramp types are proposed in order to satisfy the different operational requirements.