Pedestrian safety and efficiency at emerging alternative intersection designs with three-phase traffic signals

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Pedestrian performance of many existing intersections is poor mainly due to the minimum considerations afforded in old designs. Innovative (alternative) intersection designs may achieve better performance through a reduction in vehicle-pedestrian conflicts, cycle lengths, and pedestrian crossing distances. The focus of this manuscript is on pedestrian performance at five types of innovative intersection designs with three critical signal phases. These intersections include partial continuous flow (CFI), thru-cut, partial median U-turn (MUT), reversed reduced conflict intersection (reverse RCI) and a combination of continuous flow intersections (at one crossover) and a median U-turn (at another crossover). As four of these intersection designs (all alternatives listed except the partial CFI) are relatively new, there are currently no publications available regarding their pedestrian performance, to the best knowledge of the authors. The evaluation was done through a wide range of simulation scenarios in PTV VISSIM and through the application of NCHRP Report 948’s 20-flag method. We found that the service provided by three-phase designs may be better than a conventional design with a four-phase traffic signal. We expect that the findings of our analyses will motivate departments of transportation to test their own three-phase solutions in an attempt to improve a restricted spot.