Safety Performance Analysis of Alternative Intersection Implementations in Alabama

Abstract

Much attention has been drawn to intersection safety in recent years. This research aims to develop quantifiable safety benefits, specific to Alabama, for alternative intersection designs such as roundabouts, RCUTs, and CGTs. Methodologies performed include, a simple before- after and a comparison group analysis. The simple before-after analysis results showed that roundabouts, RCUTs, and CGTs reduced total crashes per year by 17.1%, 23.9%, and 21.2%, and fatal and injury (FI) crashes per year by 48.2%, 60.5%, and 30.2%, respectively. The comparison group analysis resulted in total and FI CMFs of 0.38 and 0.20 for roundabouts, 0.60 and 0.26 for RCUTs, and 0.79 and 0.58 for CGTs. Additional safety performance assessments were made based on prior control type, area type, and changes in the manner of crash types before and after implementation. Knowledge of the safety performance of these design alternatives will aid future research and support further implementation.