I lived in California in the 80's. They allowed this to prevent air cooled bikes from overheating in freeway rush hour traffic where speeds would reach an incredible 3 or 4 MPH for long stretches of roadway and bike were only supposed to go about 15 or 20 MPH. Bikes have improved and this is no longer an issue. Any attempt to promote this here is for selfish reasons alone and I say this as a bike rider myself.