If anything, a lower limit would act as an even greater deterrent to those drivers who believe that they can risk a certain number of drinks and still be in a fit state to drive. If they know that the legal amount of alcohol is closer to zero, even some of the "hard core" you mention are surely less likely to take such a risk.
Virtually everyone concerned about deaths on our roads has registered their approval of lowering the limit from 80mgs of alcohol per 100mls of blood to 50mgs - including the police.
Indeed both the Government and the police agree that such a reduction would save in the region of 50 of the 500 lives lost every year due to drinking drivers.
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