Despite it being cited often by both motorists and cyclists, there is no such impediment rule. §545.363 (concerning minimum speed regulations) states simply that “[a]n operator may not drive so slowly as to impede the normal and reasonable movement of traffic, except when reduced speed is necessary for safe operation or in compliance with law.” Given the physical limitations of a bicycle and its operator, it is not safe or reasonable to expect a cyclist to match, much less maintain, the prevailing speed possible by a motor vehicle. This section goes on to state, “[i]f appropriate signs are erected giving notice of a minimum speed limit adopted under this section, an operator may not drive a vehicle more slowly than that limit except as necessary for safe operation or in compliance with law.” Again, an exception is implied if the vehicle in question is unable — due to safety or physical limitation — to meet the posted minimum speed.

The statute concerning operation of a bicycle in a vehicular manner (§551) makes no mention whatsoever about impediment issues, except with respect to riding two abreast.

Thank you for the refresher. I have revised the applicable passage in the penultimate paragraph accordingly. Hopefully, it will meet with your approval and will more accurately reflect the law and reality.

If the a lane is less than fourteen feet wide, there is no “unless” or “so long as” clause. It is the cyclist’s discretion alone to travel in the lateral position he so chooses without any other statutory considerations. (Other than a bike lane.)

Consider: “A person operating a bicycle on a roadway who is moving slower than the other traffic on the roadway shall ride as near as practicable to the right curb or edge of the roadway, unless: the person is operating a bicycle in an outside lane that is: less than 14 feet in width and does not have a designated bicycle lane adjacent to that lane, OR is too narrow for a bicycle and a motor vehicle to safely travel side by side.”

If such conditions are met, the cyclist defines what is the “reasonable flow of traffic” until the lane changes to a non-exceptional condition. That is, the lane widens enough to become safe for a motorist and a bicycle to operate side-by-side, or the lane widens to more than fourteen feet. Only then is the cyclist obligated to move aside for overtaking traffic.

Your conditional language does not come from the statute. (“… so long as doing so does not impede the reasonable flow of traffic.”) It is, perhaps, a common imaginary law?