The Effects of Grade on Gap Acceptance at the University Roundabout in Fairbanks, Alaska

Abstract

The purpose of this study was to analyze gap acceptance at the University roundabout. Values for critical gap calculated from this data can be used to predict the capacity of a roundabout. After videotaping traffic, the data was reduced and analyzed using both Greenshields’ and Raff’s (both graphical and equation based) methods. The variable being evaluated was whether grade of a roundabout approach has an appreciable effect on gap acceptance. After evaluation it was determined that the differences were not statistically significant, and that, therefore, the difference in grade of the approaches did not have an appreciable effect on gap acceptance for the roundabout.