California’s “Three Feet For Safety Act” went into effect Tuesday, requiring drivers to keep at least three feet away from on-road bicycles when passing. Where roadway conditions do not allow for passing while maintaining the three foot clearance, drivers must refrain from passing, and instead slow to the speed of the bicycle until roadway conditions allow for a safe passing with a three-foot buffer.

While maintenance of a safe distance sounds good in theory, the Act is already being criticized for being near impossible to comply with in urban areas, such as downtown San Francisco, where lanes and streets are narrow and busy. Some believe that if drivers adhere to the new law, this will grind traffic to crawl in already congested and bottlenecked areas.

There are also enforcement issues associated with the Act, and possible inconsistencies between the law and the design of existing bicycle infrastructure. For example, in some urban areas with narrow roadways, a bicyclist could be within three feet of a vehicle even where the bicyclist is within a marked on-street bicycle lane and the car is within an adjacent vehicular lane. It is also typically accepted practice for bicyclists to pass vehicles stopped at a stoplight to proceed to the front of the lane where the bicyclist is more visible. Whether these situations will trigger infractions under the Act remains to be seen. Notably, the new law does not clarify what happens when it is a bicyclist that comes within three feet of a vehicle, and not the other way around.

For now, it is unclear whether the Act will actually improve bicyclists’ on-street safety, but it certainly cannot act as a replacement for well-planned bicycle transportation infrastructure and “Complete Streets” planning and design that considers and safely accommodates all modes of transportation.