daveg wrote: ...Isn't this about intention?...
I'd say yes and no. On a broader scale you are right, IMO, in that the most of the drivers in the cases which tend to be both reported and then discussed on here, were probably only behaving in a manner that's come to be seen as normal, bad driving isn't an inevitable fact of life.
It seems to me then, that the question is can the legal system do anything about it? More specifically, does deterrent sentencing work? All sorts of evidence both ways there, of course, but as others have suggested, the mandatory disqualification element of the breathalyser legislation certainly made people think.
The sometimes apparently harsh sentences that people highlight in debates like this also tend to show that some sentencers at least believe in the deterrent sentence when there's a threat from great unwashed. The message went out last summer during the rioting, for example that exemplary sentences were going to be the order of the day. Over the years, I remember others - so-called football hooliganism being associated with Leeds being one. Holiday makers with a sense of humour faced with airport security has been other.
One obvious problem is with the number of people whose job depends on their driving licence, but it's arguable that mandatory driving bans for a wider range of offences might make people in that position take a tad more care. A greater use of driving bans rather than fines might also deal with that other - largely unreported issue - of the substantial amount of fines that are never paid, especially if the various types of fine write-off are not included.
Of course, driving bans only work to the extent that they are observed. I suspect that the type of driver I'm talking about, the "otherwise law-abiding" driver would be deterred by the threat of mandatory bans, if only because of the threat to their livelihood.
The point I would then make is that this general improvement in driving behaviour would inevitably reduce the number of collisions resulting in injury or death. The reduced number of cases which did occur might then be appropriate for a more severe sentence.
(FWIW, I think the criminal court system has proved to be quite ineffective as a way of dealing with driving. I've argued before on here that there should be an administrative way of suspending the driving licences of people who collide with things and people.)