The current laws are ineffective as a deterrent or punishment and do not prevent repeat offenders. Lives and families can be saved by improving them.
The current penalties for driving a vehicle while intoxicated are currently far too light. On average 3000 people a year are killed and many more injured purely as a consequence of another persons negligence.
The penalties need to be stiffer to discourage those who would think about driving drunk, and to punish those who throw reckless abandon to the law.
I would propose a zero-tolerance approach, as there really is no excuse. One does not 'accidentally' drink several pints and then 'accidentally' drive a vehicle.
I would advocate disqualifying a driver on a first offence (requiring them to retake their test) and a mandatory 3 year ban if they seriously injure someone on a first offence. Multiple offences should carry lifelong driving bans and jail sentences for causing death or disability as a result of drunk driving.