Complete twaddle.
Whether or not the UK enters into the Cross Border Enforcement Directive foreign drivers can be and are prosecuted for motoring offences in the UK. The situation will be unchanged from how it operates now. To say that foreign drunk drivers will somehow escape punishment because the UK isn't signing up to the directive is sensationalist clap-trap of the worst kind. The only thing that the directive would permit that doesn't happen today is prosecution by post for automatically detected offences like speedcams (shame).
What people neatly sidestep when they bang on about this directive and the benefits it would bring are the barriers to defending an allegation of misdemeanour that would acompany them. Let's say you were on holiday in France, hired a car, and upon your return received the equivalent of a UK fixed penalty notice for an offence apparently commited by that vehicle but on a date/time or place that you were not driving it. How would you defend the charge? Would you spend hundreds or perhaps thousands of pounds on travel and accomodation so that you can defend yourself in a French court? Probably not, so you'd be unjustly punished for an offence you didn't commit.
If the offence is serious (e.g. drunk or dangerous driving) then the foreign driver will be processed in the same way as a UK driver and vice versa. If it's a roadside stop for speed limit infraction the same applies. As I say, it's only the camera-based offences that "escape" and in the whole scheme of things I doubt contravention of a bus lane is that important.
) would be available to the police in any other EU member country.
