YOUR report on drink-driving headlined ‘Bid to devolve power for random breath-tests and give alcohol limit teeth’ (News, 23 November) associates the reduction from 80 to 50 mg/decilitre of blood with the breath test. In fact, very few drivers are convicted after a blood test.
Most are convicted after a breath test, initially at the roadside but later with more accurate equipment in a police station. This test has a limit at the moment of 35 micrograms per decilitre (there is also a urine test with a limit of 107 mg/decilitre).
Reducing the blood-alcohol limit to 50 mg (0.05 per cent BAC) would need to be accompanied by a corresponding reduction in the other limits: presumably (by rounding) to 22 micrograms per decilitre of breath and 67 mg of urine. However, I have seen no reports of this.
Steuart Campbell, Edinburgh