There are both implicit and explicit hazards introduced by segregated bike lanes on the road. By implicit hazards we mean encouraging poor position on the road — slinking along the edge to “stay out of the way”. In this article, we discuss the explicit hazards.
Explicit hazards are traps. Three of the traps are:
1. The “coffin corner”: Standard “Rules of the Road” require that someone making a right turn move first “as close as practicable” to the right edge of the road. Anyone going straight through the intersection should pass on the left.
But a bike lane stripe instructs just the opposite behavior — a right turning motorist is told to stay left of the bike lane where (s)he will cross paths with a straight-through cyclist. This risks a “right hook” collision. There is also an increased risk of collisions with left-turning motorists who are less likely to see a cyclist at the edge of the road.
2. The “door zone”: Where bike lanes are provided next to parked cars, it is very rare that they are outside the area that can be suddenly blocked by an opening car door. It takes much more than the 12 or 14 feet recommended by the AASHTO Guide for the Development of Bicycle Facilities. Door zone bike lanes create a serious hazard that causes many casualties.
3. Bike lanes on steep downhills. The photo at right shows a steep descent (7 percent grade) where the 5 feet provided in the bike lane is not nearly enough for safety.
