Guidance
Guide to methodology for drink-drive statistics
A guide to the methodology used in producing estimates in the Department for Transport's drink-drive casualty statistics.
Applies to England, Scotland and Wales
Documents
Details
In 2025, there was a change to the methodology which caused slight changes to estimates. More details can be found in the methodology note.
This guide describes the methodology used in the production of the statistic included in the publication 鈥淩eported road casualties in Great Britain involving illegal alcohol levels鈥�.
The guide covers:
- drink-drive legal limits and definitions
- data sources
- completeness of data and reliability of drink drive estimates
- adjustments to account for missing data
- uncertainty in the statistics and how it鈥檚 communicated
- timeliness of the statistics
Further information on the drink-drive methodology can be addressed to the road safety statistics team via the contact details below.
Road safety statistics
Email roadacc.stats@dft.gov.uk
Updates to this page
Published 31 July 2025