Split phasing divides the green light of a traffic signal into separate phases: one for turning vehicles and another for through-traffic and pedestrians.
- Use a five-section signal head with a combination of circular and arrow indications
- For permissive-only right-turn modes (where pedestrians continue to cross while car are permitted to turn), program the turn arrow to flash yellow to indicate to drivers that they must yield to pedestrians in the crosswalk
- For protected-only right-turn modes (where pedestrians and turning cars have separate signal phases), program the turn arrow to a steady green arrow
- Allows pedestrians to cross the street free of conflicts with turning vehicles
- Potentially increases wait times for pedestrians and the possibility of pedestrians crossing against the signal
- Split phasing may not extend to vision impaired pedestrians unless an accessible pedestrian signal is installed
Where to Use It
- Intersections with dedicated turning lanes where heavy pedestrian volumes and turning vehicles conflict, resulting in crashes or congestion
- Sections 4D.21 – 4D.24 in the Manual on Uniform Traffic Control Devices contain specific engineering guidance
- Widespread in U.S. cities
This material is the product of a partnership between America Walks and Sam Schwartz Engineering. Visit here for more information on the partnership.