The objective of this research was to examine certain aspects of passing lane operations, with a focus on 3-lane alternate passing designs in Arkansas. Aspects examined included effects of passing lane length on speed, effects of passing lane length on platooning, effects of passing lane length on passing, and crash histories of transitions and passing lanes. Five sets of field data were collected at four rural sites. Speed patterns were found to vary among sites. Platooning decreased after entering the passing lane, and eventually stabilized. Passing activity was greatest at the beginning of the segments. Five years of crash data were utilized. Even though the passing lane segment volumes were higher than the state average rural two-lane road volume, the passing lane crash rates were lower than the statewide average crash rate on rural two-lane roads. Sample size restrictions limited the information found about transition zones. The crash rates at the entering taper were less than at the ending taper. (Author/publisher)
Abstract