The goal of this project was to analyze geometric, speed, volume, and crash data for a broad range of conditions with the ultimate objective of establishing bases for warrants for right-turn lanes on two-lane roads where major approach did not have any controls. Right-turn lane guidelines for this contest is not clear and convincing. Safety effectiveness and savings were estimated using extensive data examination and analysis of crash data, several statistical models that were developed using crash data, and a conflict model, which was developed using field data. It was found that not all accidents are eliminated with use of right-turn lane. However, right-turn lanes were effective in improving safety. More interesting was the finding that safety effectiveness of right-turn lanes was more at driveways than at intersections. Operational effectiveness was estimated using a delay model and a fuel consumption model, which were developed using field data, simulation software (CORSIM®), and statistical software, Minitab®. The volume thresholds that varied with changes in right-turn lane cost and fuel cost were provided as alternative scenarios for warrants. The warrants established here will be helpful in decision-making regarding whether to implement a right-turn lane or not on two-lane roads.
