by Zoot Katz ?? Wed Apr 28, 2010 4:59 pm IMO, the single most limiting factor is IQ.I will willingly wager that the average IQ of ES members is greater than the average IQ of NASCAR fans.Research indicates that the lack of bicycle specific infrastructure is what keeps more people from cycling.I have been riding in the street since I was eight years old and he is where I prefer to ride today.