Protected Intersection
INT-PRI-11 Protected Intersection
Typical at: Compact Urban Core
Suburban is an edge case. Undeveloped and Rural contexts are an unlikely pairing.
#Design notes
The first addition to Intersections & Crossings since the original ten. Addresses a specific, well-documented failure mode of conventional intersections, insufficient separation between turning vehicles and through bicycle/pedestrian traffic, that no other pattern in the set directly solves.1
Corner islands should provide genuine physical refuge, not a painted buffer alone. Crossing setback distance should give turning drivers a clear sightline and adequate reaction distance to pedestrians and cyclists.
Compatible with, and often paired with, Roundabout (INT-RAB-01) as the default intersection treatment.
#Turning trucks
Vehicles making a turn are involved in a disproportionate share of fatal pedestrian and cyclist crashes relative to vehicles going straight, and that risk rises sharply with vehicle size.23 See Signal for the general pattern.
Where a truck route runs through this intersection, setting the bicycle stop bar back keeps a cyclist waiting at the intersection out of a turning truck's swept path. Where a bicycle signal phase exists, separating bicycle and truck turning movements in time, not just space, closes the gap a setback stop bar alone cannot.4
#Related patterns
- Roundabout (Single/Multi-Lane) (INT-RAB-01)
#References
- Precedent-based Falbo, Nick, "Protected Intersections for Bicyclists," ProtectedIntersection.com (2014).(opens in new tab)
- Evidence-based U.S. Government Accountability Office, Pedestrian and Cyclist Safety: DOT Should Take Steps to Address Risks Related to Limited Driver Visibility, GAO-26-107954 (2026).(opens in new tab)
- Evidence-based Wang, Q. et al., "Exploring the Influencing Factors and Formation of the Blind Zone of a Semitrailer Truck in a Right-Turn Collision," Sustainability 14(16), 9805 (2022).(opens in new tab)
- Precedent-based Seattle Streets Illustrated, 3.11 "Freight" (setback bike lane stop bars and bicycle signals as tools against large-truck turning movements).(opens in new tab)