dojj, thats exactly right mate. To be honest, we have never had a problem round our area with this. Everyone HAS to park half on half off. This way theres enough room for one car to get through. Its not a busy round by any means, but when most houses have 2+ cars each and only one off road parking space, it has to be done. I think local councils realise this though which is why we've never had a problem.
Theres always one 'visitor' though that decides to park fully on the road and cause chaos though.