There is evidence for effectiveness of:

1. Reductions in permitted blood alcohol levels for drivers in reducing drink-driving and related motor crashes and fatalities

2. 80mg/100ml blood alcohol concentration (BAC) laws in reducing drink-driving, drink-driving casualties and alcohol-related crashes and fatalities

3. Lower BAC laws in reducing alcohol-impaired crash fatalities among young or inexperienced drivers

4. Sobriety checkpoints and random breath testing in enforcing drink drive legislation and in preventing alcohol-impaired driving, alcohol-related crashes, and associated fatal and non-fatal injuries and crashes

Scottish policy note

Following the debate on 18 December 2008, the Scottish Parliament agreed a motion calling on the UK Government to reduce the drink drive limit from 80mg per 100ml of blood to 50mg. A commitment to pressing the UK Government for a reduction in the drink driving limit and the introduction of new police powers for random breath testing was made in the alcohol policy framework; ‘Changing Scotland's Relationship with Alcohol: A Framework for Action’ (2009).

References:

Babor, T. Caetano, R. Casswell, S. Edwards, G. Giesbrecht, N. Graham, K. et al. ( 2010) Alcohol: No Ordinary Commodity. Research and Public Policy. 2nd Edition, Oxford: Oxford University Press

Ludbrook, A.  ( 2004) Effective and cost-effective measures to reduce alcohol misuse in Scotland: An Update. Edinburgh: Scottish Executive

Mulvihill, C. Taylor, L. Waller, S. with Naidoo B. Thom, B. (2005) Prevention and reduction of alcohol misuse: Evidence briefing. Second Edition. London: Health Development Agency.

World Health Organisation ( WHO, 2009) Evidence for the effectiveness and cost–effectiveness of interventions to reduce alcohol-related harm. World Health Organisation: Europe