Following up from my recent article: Sharrows: Love ‘em or hate ‘em, I have compiled four types of sharrow applications that make sense. In no particular order:
1. Gap closure on a road that has bike lanes, bike boulevards, or off-street paths on either end. It’s tricky to state a maximum gap closure distance, but I’d say a half mile is reasonable. Could be longer depending on the circumstances.
2. On neighborhood greenways/bike boulevards as both guidance on where you want cyclists to ride and as passive identification/marketing. See the Streetfilm’s Bike Boulevards Video, and the PBOT Plan on Greenways for more information. Note that design of a neighborhood greenway/bike boulevard is intended to create a safe, comfortable shared use environment.
4. Streets where cyclists can keep up with traffic, such as on downtown Portland’s one-way streets where traffic signals are timed at 12 to 15 mph and cyclists can easily keep up.
Notice that in situations two through four, the speed differential cyclists and motorists is either low or zero.
Where should sharrows be placed? Outside the door zone (min. 11 feet from curb) where there is on-street parking. Many cities are shifting them toward the center of the lane, in part to reduce higher maintenance costs when sharrows are placed in a motor vehicle wheel path. From what I’ve seen so far, this makes sense, depending on the circumstance.