Safety Comparison of Smart and Standard Channels Based on Sight Distance and Conflicts

Vehicle movements through intersections can be improved by channelization, by including separate channels for the right turn movements. A standard channel provides an entrance angle greater than 90°, while a smart channel design is a modified right-turn channel that decreases the channelized right turn to approximately 70°. This study compares whether the different configurations have different safety performances based on conflicts and sight distance. Vehicle interactions were manually identified using Post Encroachment Time (PET). A total of 805 interactions with PET less than or equal to 3s. were observed, involving the total movements of 58,546 right-turn and through vehicles on eight different channels. The means of the five safety performance parameters in this study were significantly higher at standard channels than at smart channels. Ordinal logistic regression results indicated that the probability of a potential conflict having a high severity is 4.1% higher at smart channels than at standard channels