Londondrz, you mean the Police etc? Want me to ask them on Twitter?
It would be nice if there were a way to build out the entrance to make the turn in from the top very difficult, but I'm sure the DGAF crew would just inconvenience everyone on the main road, while they manoeuvre in.
PS, my comment about the croc teeth was mostly in jest, but if such a thing were ever put in, most systems have a workaround, a lockout for emergency vehicles. Just like fire gates etc. Not that it is a possibility, just pointing it out.
Maybe even just some "camera enforcement" signs at the entrance would deter 1 or 2 a month.