Open Data & The New Scottish Drink Driving Law

15 December 2014

At Storm we support open data for a number of reasons. Data that is open:

  • has significant potential for re-use in other digital services
  • will help the discovery of new and innovative solutions to societal problems;
  • can drive efficiencies by enabling frictionless sharing of information between public bodies
  • can help foster participation of citizens in political and social life

It is on this last point, fostering participation of citizens in political and social life, that we decided to use open data to help raise awareness of the new drink driving law that was introduced in Scotland on December 5th 2014.

The new limit in Scotland is 50 milligrams of alcohol per 100 millilitres of blood, reduced from 80 milligrams of alcohol per 100 millilitres of blood. The breath alcohol equivalent of the new limit is roughly 22 micrograms of alcohol per 100 millilitres of breath; reduced from 35 micrograms of alcohol per 100 millilitres of breath.

At Storm we wanted to put together a series of data visualisations of all people in Scotland who have been breath tested over the last three years in order to:

  • help demonstrate the value of open data to support awareness raising marketing campaigns
  • Improve understanding of the drink driving problem among the general public
  • Demonstrate the potential impact of the limit change to drivers who regularly have one drink and drive

Unfortunately Scotland does not yet collect and publish this type of data in an open way. As such we had to use the equivalent data from England and Wales, between 2009-2013. This data was published on

Key Findings

We are not experts on the subject. However we have chosen to highlight a few points demonstrated by the data:

New Limit Vs the Old Limit

New drink drive limit vs old limit

New drink drive limit vs old limit

The above graph shows the total number of breath tests taken during 2013 which had a result with a higher reading than 22mg (blue line – the new limit) and a higher reading than 35mg (black line – old limit). In total 51,151 people were found to be over the limit during this period. A total of 13,824 people were breath tested and found with breath alcohol limit between 22mg and 35mg.

Men V Women

Men vs Women

The overwhelming majority of people who drink drive are men. Potentially the new law may impact men more than women as the data shows men are more likely to have one drink and then drive than woman. Circa 11,000 men who were breath tested last year in England and Wales and tested negative would now be over the limit under the new Scottish regulations.


Age Bands

Age Bands

The age band with the highest number of drink drive offences is between ages of 30-39. This is followed by 20-24, 25-29 and then 40-49.

Time of Day & Time of Year

time of day and year

time of day and year

Unsurprisingly the worst times for catching drink drivers are between 8pm-12pm. Perhaps more surprisingly there are slightly more people found drink driving in June than in December.  

So what?

We published this visualisation not so much to make a point about the drink driving law, rather to demonstrate how open data can be used to engage citizens in issues that matter to them.

We believe the open data policy published by the GDS which states that, all public data should be published in a machine-readable, reusable form unless it is private data collected from people or restricted for national security reasons, should also be followed and implemented across Scotland.

While there are pockets of excellent work on open data across Scotland including local authorities and the NHS it is important to note that making public data open is the first step. The goal is to derive value from open data and encouraging use of it by policy makers, web developers and the public. This is just as important.




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