Scotland’s lower drink drive limit is yet to have an effect on road traffic accidents / deaths and this may be down to a lack of enforcement of the law since its introduction in December 2014, according to a study published in The Lancet.

Basing on their observations of a natural experiment – the change in blood alcohol concentration (BAC) for drivers in Scotland from 80mg alcohol per 100ml blood to 50mg – researchers compared the estimated effect of the intervention on road traffic accidents between 1 January 2013 and 31 December 2016 with that of England and Wales, where the legal BAC limits stayed the same.

They found no significant change in Scottish road traffic accident (RTA) rates after the reduction in BAC limits, and a 7% increase in weekly RTA rates in Scotland, relative to England and Wales.

One plausible explanation for the results, the researchers suggested, was that the legislative change was not suitably enforced, for example, with random breath testing measures.

‘Our findings suggest that changing the legal BAC limit for drivers in isolation does not improve RTA outcomes’, something that has significant policy implications internationally as several countries and jurisdictions consider a similar reduction in the BAC limit drivers.

Bans and breathalysers?

The news from Scotland has not deterred public sentiment for more restrictive drink drive measures. First, online garage and car repair marketplace’s survey of one thousand of its drivers found that more than 900 of them would want to help reduce the amount of accidents caused by drink-driving in the UK, by putting breathalysers in cars.

Then a poll of 2,000 drivers from law firm Slater and Gordon found 84% want to see the limit reduced in order to cut the number of casualties on the country’s roads, with 54% in support of a total ban on having alcohol in your system when on the road.

However, when asked about personal drink-driving habits, many drivers seem to believe that they could take risks and still be able to fly under the radar. 38% of those surveyed confessed to getting behind the wheel when they knew or suspected they were not fit to drive.

Paul Reddy, head of road traffic defence at Slater and Gordon, said:

‘There is still a lot of confusion around the drink drive limit in this country, but it is surprising and very concerning that the large majority still don’t know the guidelines.

‘This may be one of the reasons why so many people support a total ban which would remove any room for doubt. What these results do definitely tell us is that more education is needed on this.’

A joint survey of similar proportion between and YouGov found that almost one in five (17%) would find drink-driving acceptable if they personally felt unaffected by it and nearly one in ten reckoned they could drink more than the UK legal limit before their driving ability would be impaired.

Meanwhile, elsewhere…

On the other side of the Atlantic, one state authority is pressing ahead with implementing a lower limit. On 30 December 2018, Utah becomes the first and only state to take action on the United States (US) National Transportation Safety Board’s (NTSB) recommendations to lower BAC limits to 50mg per 100ml.

Under the new law, a person will also be charged with ‘automobile homicide’ if they kill another person while operating a vehicle with a blood alcohol concentration (BAC) level of 50mg or higher — considered a third-degree felony.

While The Lancet’s results are yet to show a reduction in overall RTAs, it is worth noting that legislation to decrease the legal limit is focused on drink drive accidents in particular, and as a such, the scope of the law in influencing RTAs overall is limited.

Furthermore, as the US NTSB pointed out in its assessment of the evidence, the trend towards a lower limit is overwhelming – more than 100 countries have so far adopted a limit of 50mg /100ml or lower, and with Utah setting the pace, the push to drive the limit down in more places seems inevitable.