If the Drive is fairly narrow, it would be VERY SENSIBLE to Clip the pipe at a Height above which impact by a Vehicle is unlikely, The Gas Safety & Use Regulations stipulate that gas pipework should be protected from risk of damage,.. surely this is just common sence, oh and by the way, only a couple of weeks ago I was called to a gas escape caused by a car scraping a low level copper pipe along a drive, we re-routed pipe at high level to prevent a re-occurance
www.elanar.co.uk, July 2009