Seriously?? 18 inches and I would be sweating bullets. That is close enough to reach out and touch the car. Way too close to be considered safe. What happens if my chain slips and I veer left? What happens if a gust of wind comes and blows me left? What happens if I get a blowout and fall left? 18 inches gives no room for error.
PA's law says to give 4 feet, and while I think that's overkill, I don't feel that it was a safe pass unless the give at least 2 feet, more if the speed differential is higher.
Last edited by spivonious; 11-25-13 at 11:10 AM.