Source: SF Bicycle Coalition
“Turn From the Curb”
How is a car supposed to make a right turn from a street with a bike lane? It’s one of the most widely misunderstood traffic rules (at least in California). Most people don’t know the law, and the DMV doesn’t express the concept as clearly as they should. So, hopefully this page will help explain the issue a little better!
A right-turning car is supposed to move into the bike lane before the intersection, anywhere from 200 to 50 feet before, first signalling the lane merge, then merging right to the curb lane, then finally making the actual turn when safe.
The guiding principle is to always make a right turn from the right lane — or “Turn from the Curb.” Turning across lanes is a big no-no, since it can result in crashes and near-crashes, especially “right hook” collisions. According to 2011 data from SFPD, “Unsafe Turn without Signaling” was the top cause of injury crashes for SF bicycle riders.
A bike lane is a travel lane, like a standard travel lane — and you should always turn from the lane closest to the curb. To make a right turn, any vehicle (bike, car, truck, etc) is supposed to be in the right lane, so a motor vehicle needs to safely merge into the bike lane (yielding to any traffic already in that bike lane), before making the turn. That’s why bike lanes, like this Valencia Street photo shows, are dashed when approaching an intersection. Dashed lanes tells drivers they can merge before turning right.
In San Francisco, streets with bike lanes have the left sideline of the bike lane dashed (or sometimes dropped altogether) the last 50-200 feet before an intersection. Unfortunately, few people know what that means, but each month, our instructors are teaching all new taxi drivers and bicycle riders about this rule, and so much more!
Here are the pertinent parts of the California Vehicle Code (CVC):
Turning Across Bicycle Lanes
21717. Whenever it is necessary for the driver of a motor vehicle to cross a bicycle lane that is adjacent to his lane of travel to make a turn, the driver shall drive the motor vehicle into the bicycle lane prior to making the turn and shall make the turn pursuant to Section 22100 [general turning regulations].