Louise, I agree with what your saying about catching people speeding etc, but not other dangerous drivers. It is so much easier for the police to stick speed cameras up and catch anyway who goes slightly over the limit and then fine them all rather than having to make an effort to go out and find people who are drink driving etc. Whilst speeding is obviously wrong, like you have said, they are more accidents cause by other reasons than some who was a few mph over the limit.
With regards to the driving curfew idea, like has been said, the people who really are the problem will most likely ignore it anyway and the people who try and drive safely and carefully day or night will lose out. People spend a huge amount of time and money getting their licence, money on a car, insurance etc and then to be told that you can only drive at certain hours seems very unfair. This idea could be taken to the extreme - the are more accidents during the rush hour (morning and evening) than during the day, so young drivers shouldn't be allowed to drive then? There are alots of accidents in busy towns etc? Whilst I realise that it may be a good idea, and could potentially save lives, I don't know as it is fair or would work if put into practice.
Out of interest, does anyone have a link for the article - I'd like to read it.