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The Vision Zero program in the District of Columbia, USA (the District), aims to eliminate traffic fatalities and serious injuries by 2024 through solutions focused on engineering, education, and enforcement programs. No Turn on Red (NTOR) is one of several engineering solutions identified in the program for rapid design and implementation. Currently, limited federal or local guidance is available to aid in the selection, implementation, and evaluation of right-turn-on-red restrictions on a large scale. Rather, NTOR prohibitions are traditionally evaluated on a case-by-case basis.
In late 2018, the District Department of Transportation (DDOT) selected 100 pilot locations for NTOR implementation to protect non-motorized roadway users such as pedestrians, schoolchildren, and cyclists. The selection process was based on the level of pedestrian activity, proximity to pedestrian generators (such as schools or metro stations), crash history, and geometric or operational characteristics. The project team completed a before-andafter study to quantify and assess the impact of these new restrictions to determine if future expansion of the restrictions was feasible.
NTOR restrictions have previously been implemented in the District based on prior studies and analysis. Therefore, some of the pilot locations had a partial (time of day) or full-time NTOR restriction on one or more approaches in the before condition. However, the partial restrictions were changed into full-time restrictions and the new signs were installed at consistent, highly visible locations at each intersection.
Observations and Analysis
1. Data Collection.
The AM and PM peak hours for the study intersections occurred between 7:00 a.m. and 9:00 a.m. and 4:15 p.m. to 6:15 p.m., respectively. Off-peak hours were defined as 11:00 a.m. to 1:00 p.m. and 7:00 p.m. to 8:00 p.m. for the afternoon and evening periods, respectively. The "before" or pre-evaluation was conducted from February 2019 to March 2019. The "after" or post-evaluation was conducted from April 2019 to May 2019 after an adjustment period of at least 4 weeks following installation of the new NTOR signs. Data was available for both the before and after periods at 74 locations, which were the focus of this study.
Each intersection was surveyed during a peak hour and off-peak hour. Intersections were assigned to either an AM Peak or PM Peak based on the whichever peak had the higher total right turning...
