Operational Performance Evaluation of Different Exit Ramps on Florida's Freeways by Considering Number of Lane Change

Abstract

In the State of Florida, several types of exit ramps are used for traffic to exit our freeways, especially four typical types, which are single-lane exit ramp with a taper, single-lane exit ramp without a taper, two-lane exit ramp with an optional lane, and two-lane exit ramp without an optional lane. Drivers exiting freeways need to make decisions and execute maneuvers (i.e., lane change or lane merge) prior to the exit ramp in order to access cross roads at the interchanges. And different types of exit ramps lead to different driving maneuvers when exiting (fast-paced deceleration, lane changing, merging, unbalanced lane utilization), which also affects the operational performance on freeways. Bases on the facts, there are several issues and concerns that need to be addressed in selecting the most optimum types of freeway exit ramp(s) to use at a given interchange. This paper mainly focuses on different impacts of number of lane change by different types of ramp. A data collection of 24 sites were conducted to help set up a mathematical model, which could estimate the number of lane change by considering several possible independent variables. Results of the model could help choose optimal ramp type.