Dave, judging from the lack of responses, I wonder if others are as mystified as me as to what you actually mean. Perhaps if you can elaborate you might get something useful in reply

You shosuld have a visitor book/list as part of your presence recordimng system, so you know who is on site in an emergency, That list should include number plate of vehicles in case they are reported parked somewhere, blocking pedestrian routes etc., and need to move vehicle quickly.

As someone who visits many different sites I see a wide variety of systems. These range from an oil terminal (reverse parking, vehicle to be left unlocked with key in ignition) to a simple visitors' parking area and nothing more or just verbal instructions as to where to go to park and unload my equipment. ("Do I know where Occupational Health is? OK!" Some high risk sites allow me to drive unaccompanied, other lower risk sites insist that I am accompanied. There does not seem to me to be any (to me logical) system as to what the arrangements should be. Chris

Hope this isn't for a Tesco car park? I would not manage to pick up a loaf and a dozen eggs for fear of infringing the car park rules!