Theses and Dissertations Collection

Passing maneuvers by drivers on rural two-lane highways consist of many potential crash risks. These maneuvers by drivers are made up of complex decisions such as: judging the speed of the approaching vehicle, interpreting the speed of the oncoming vehicle, and managing travel speed and location while in the opposing lane. When this passing maneuver is influenced by roadway geometric conditions such as horizontal curvature, passing decisions become more complicated as sight distance may be restricted, increasing potential crash risks.

This research conducted a laboratory experiment evaluating effects of horizontal curvatures on passing maneuvers. A driving simulator at the University of Idaho was used to develop a virtual scenario of three real-world highway sections in Alaska which currently experiences high crash rates. Twenty-four participant drivers were tested using this virtual scenario. The results suggest the left-hand orientation curves and right-hand orientation curves did not have significant difference in passing maneuvers on these real-world sections. The passing maneuvers were mostly affected by radius of the curves.