Channelized Right-Turn Lanes
NCHRP Project 03-89, Channelized Right-Turn Lanes, Active TRB Project. MRIGlobal submitted the final report for this project in July of 2011. As indicated in the summary for NCHRP Project 3-72, the study of the channelized right-turn lanes exceeded the available budget and so was deemed outside the scope of that project. Subsequently, NCHRP Project 03-89 then directly focused on the design and use of channelized right-turn lanes. In addition to developing a state-of-practice summary, the project team performed research targeted on developing design guidance for channelized right-turn lanes that would balance the needs of all users (bicycles, pedestrians, motor vehicles). MRIGlobal performed field observational studies, interviewed professionals in the areas of orientation and mobility, used micro-simulation to assess optimal operations, and performed a safety assessment. General findings and recommendations are as follows: The project team observed that crosswalks are often located near the center of the channelized right-turn and encouraged consistent design, traffic control, and crosswalk placement. At locations where the right-turn lane has a STOP sign, the crosswalk should be immediately downstream of the stop bar. At other locations, the crosswalk should be located near the center of the turn since the majority of those observed (70 percent) occurred at this location. Channelized right-turn lanes with yield control reduced delay to turning vehicles by 25 to 75 percent when compared to traditional right-turn lanes. An increase in the turn radius can further reduce right-turn delay by 10 to 20 percent for each 5 mph increase in turning speed. The use of raised islands should be considered when needed for pedestrian refuge, particularly at locations where a two-phase crossing approach may be needed by the pedestrian. Pedestrians who have vision impairments experienced a more difficult time crossing channelized right-turn lanes with acceleration lanes, so the use of acceleration lanes at the downstream end of the turn should be reserved for locations with very little pedestrian activity. Traffic signals should be adjusted to include a pedestrian-actuated signal at channelized right-turn locations and, where possible, include an overlap phase to provide additional green time to right-turning vehicles when needed.