Cyclists in South Dakota would be required to get off the road and dismount from their bikes to let faster-moving vehicles pass them under proposed amendments to existing state law.

The planned changes would also remove their right to ride in primary position where road width makes it unsafe for cyclists and motorists to travel alongside one another.

According to Cycleicio.us, a bill introduced to the state house of representatives last week has been sponsored by around one in 10 members both of that house and the state’s senate.

Currently, cyclists riding “at less than the normal speed of traffic” are required to “ride as close as practicable to the right-hand curb or edge of the roadway,” with some exceptions.

Those are “to overtake and pass another bicycle or vehicle proceeding in the same direction, to prepare for a left turn at an intersection or into a private road or roadway, or to avoid conditions including, but not limited to, fixed or moving objects, parked or moving vehicles, bicycles, pedestrians, animals, or surface hazards, or substandard width lanes that make it unsafe to continue along the right-hand curb or edge.”

The proposed amendment to that law will remove that exception for substandard width lanes, which are defined as “a lane that is too narrow for a bicycle and vehicle to travel safely side by side within the lane.”

It would also introduce a new clause as follows: “If a person is operating a bicycle within a no passing zone on a roadway that has no shoulder or a shoulder of less than three feet in width, the person shall stop the bicycle, move the bicycle off the roadway, and allow a faster vehicle to pass.”

The bill’s prime sponsor is the chair of the state House Transportation committee, Mike Verchio, who according to Cycleicio.us consistently votes against legislation aimed at improving road safety, for example laws regarding use of mobile devices while driving, but supports higher speed limits.

Currently, there is no state-wide cycle campaign group in South Dakota, although a local blogger from Sioux Falls is hosting an online meeting today to bring cyclists together.

Tim Rangitsch from bike shop Acme Bicycles in Rapid City told local TV station KOTA: “I mean this new law to actually restrict to actually dismount and exit the roadway is impractical and fairly unenforceable.

“It’s very unsafe for the cyclist and the motorist. I don't think this bill is very well thought out. In fact, I think it’s asinine.”

You could be forgiven for thinking that there is some kind of competition running in the US to see which state can introduce the most baffling piece of legislation related to cyclists.

Earlier this month, we reported on a bill in Missouri that, if enacted, would require riders to attach a fluorescent orange flag on a 15 foot pole to their bikes.

> Proposed Missouri law to make cyclists carry 15ft high flag

And this week, the Tennessee senate passed cycle helmet legislation that makes no mention of bicycles, cyclists, or indeed helmets.

Tabled last year, the bill was aimed at requiring the state’s Department of Education to include advice on "the proper use and positioning of bicycle helmets” within a cycle safety programme aimed at schoolchildren.

Yesterday, the entire original wording of the bill, other than the title, was struck out and replaced by clauses forbidding Tennessee school systems from deducting union subscriptions from teacher’s pay cheques.

The amendment - allowed because it makes changes to the same state education law contemplated by the bill as originally framed - was passed despite some senators asking for time to consult local education figures and claims that it was anti-union, reports TimesFreePress.com.

Senator Jeff Narbro described it as a “terrible bill that targets teachers. This was a lot better bill when it was about bicycle helmets."