Reported road casualties in Great Britain, final estimates involving illegal alcohol levels: 2020
Published 28 July 2022
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This publication is available at https://www.gov.uk/government/statistics/reported-road-casualties-in-great-britain-final-estimates-involving-illegal-alcohol-levels-2020/reported-road-casualties-in-great-britain-final-estimates-involving-illegal-alcohol-levels-2020
This publication presents final estimates of casualties arising from reported collisions involving at least one motor vehicle driver or rider over the legal alcohol limit for driving, in Great Britain in 2020. Figures are derived from the STATS19 forms completed by the police plus toxicology data for road fatalities from coroners and procurators fiscal. This is an update, based on more complete data, of the provisional 2020 estimates which were published in February 2022.
The recent trends in reported road casualties have been impacted by the national restrictions implemented from March 2020 onwards following the coronavirus (COVID-19) pandemic. More information can be found here in our release The impact of lockdown on reported road casualties in Great Britain.
Main points
Final estimates for 2020 show that between 200 and 240 people were killed in collisions in Great Britain where at least one driver was over the drink-drive limit, with a central estimate of 220 deaths.
The final estimate of fatalities for 2020 is broadly in line with the last few years and is not statistically significantly different from 2019 at the 95% confidence level.
Chart 1: Fatalities in reported drink-drive collisions: GB, 2010 to 2020; error bars show 95% confidence intervals
An estimated 6,480 people were killed or injured when at least one driver was over the drink-drive limit. This represents a fall of 17% from 7,800 in 2019 and is the lowest figure recorded.
The total number of collisions where at least one driver was over the alcohol limit decreased by 14% to 4,620 in 2020, the lowest number of drink-drive collisions recorded.
It is important to note that the number of reported drink-drive collisions and casualties involved in them is likely to have been impacted by the COVID-19 pandemic in 2020 and the national restrictions implemented from March 2020 onwards leading to a reduction in traffic and collisions. The falls in drink-drive collisions between 2019 and 2020 are broadly in line with the reduction in overall road collisions over the same period.
Chart 2: Drink-drive fatalities, Killed or Seriously Injured (KSI) casualties and total casualties: GB, 2020
Casualties in drink-drive collisions in 2020
Drink-drive fatalities
These statistics, especially the number of fatalities, are subject to considerable uncertainty (see sampling uncertainty below). This means that it is impossible to be sure of the precise number of fatalities, so ranges and confidence intervals are used for fatalities throughout the publication.
The 95% confidence level is the standard against which statistics are typically tested. The bars on chart 1 are ranges of values for an estimate which we are 95% confident that the ‘true’ value falls in. Technically, it indicates that in 100 years with the same risk of fatalities (or injury), 95 of those years will result in a number of fatalities (or injuries) between a given range.
When we compare figures for the latest year with the previous year, we say that a change is ‘statistically significant’ if we are sufficiently confident (at the chosen level – here, 95%), based on the data available, that the difference between the two figures is the result of a genuine change, rather than being a product of chance - broadly, this is when the two sets of bars on chart 1 don’t overlap. Otherwise, we say the change is ‘not statistically significant’ – this does not necessarily mean that there is not a genuine change, but that we are not able to determine one exists from the data available, at the chosen level of confidence.
The final central estimate of the number of deaths in collisions with at least one driver over the alcohol limit for 2020 is 220. This represents about 15% of all deaths in reported road collisions in 2020. The central estimate for 2020 is lower than the final figure for 2019, but the decrease is not statistically significant. The 95% confidence range indicates that we can be 95% confident that the true figure is between 200 and 240 fatalities.
The final estimate for 2020 is based on coroners’ and procurators’ fiscal reports for 77% of the drivers or riders who were killed in road traffic collisions in that year in addition to breath tests taken at the scene where the driver was not killed (see definitions below).
The prevalence of drink-driving in road deaths has fallen over time. In 1979, 26% of road deaths occurred in collisions where at least one driver or rider was over the drink-drive limit. This had fallen to 15% by 1989. Since then the percentage of road deaths that are drink-drive related has varied between 12% and 18%. In 2020, the rate was 15%.
Chart 3: Fatalities in reported drink-drive collisions, as a percentage of all fatalities: GB, 1979 to 2020
Drink-drive killed or seriously injured (KSI) casualties
The central estimate of the number of killed or seriously injured (KSI adjusted) drink-drive casualties in 2020 is 1,490, a decrease of 22% on 2019. This is the lowest level recorded.
For details on adjustments for non-fatal casualties see the changes in systems for severity reporting section below.
Chart 4: Killed or seriously injured (KSI adjusted) casualties in reported drink-drive collisions: GB, 2010 to 2020
The proportion of killed or seriously injured (KSI adjusted) casualties in drink-drive collisions has varied between 5% and 7% since 2005. In 2020, the rate was 6%.
Chart 5: Killed or seriously injured (adjusted) casualties (KSI) in reported drink-drive collisions, as a percentage of KSI casualties: GB, 2005 to 2020
All drink-drive casualties
The central estimate of the number of drink-drive casualties of all severities in 2020 is 6,480, a fall of 17% from 7,800 compared to 2019. This is the lowest level recorded.
Chart 6: Total casualties in reported drink-drive collisions: GB, 2010 to 2020
It is estimated that around 6% of all casualties in reported road collisions in 2020 were involved in collisions in which at least one driver or rider was over the drink-drive limit.
In 1979, 9% of road casualties occurred in collisions in which at least one driver or rider was over the drink-drive limit. This fell to 5% by 1992 and has mainly varied around 5% since then.
Chart 7: Casualties in reported drink-drive collisions, as a percentage of all casualties: GB, 1979 to 2020
Number of drink-drive collisions in 2020
Trends in drink-drive collisions are similar to those for casualties.
There were an estimated 200 fatal drink-drive collisions in 2020 unchanged from 2019.
The total number of drink-drive collisions of all severities fell by 14% from 2019 to 2020 to 4,620, the lowest number recorded. This means that around 5% of all reported road traffic collisions in 2020 involved at least one driver or rider over the legal alcohol limit.
In 1979, 8% of reported road collisions were drink-drive related. This fell to 5% by 1990 and has generally been around 5% since then.
It is important to note that the number of overall road traffic collisions has fallen, from 254,967 in 1979 to 91,199 in 2020, a 64% reduction. However, drink-drive collisions have fallen further; down 76% since 1979. It is therefore likely that some drink-drive initiatives have been effective in reducing the number of drink-drive collisions.
Chart 8: Reported collisions and drink-drive collisions: GB 1979 to 2020 (index 1979 = 100)
Drink-drive casualties by country and English region
Overall, 6% of casualties in reported road collisions in 2020 occurred in collisions in which at least one driver or rider was over the drink-drive limit. This varied across the countries of Great Britain. Scotland has a lower drink-drive limit (22 micrograms(mg) per 100 millilitres(ml) of breath or 50 mg per 100ml of blood) than England and Wales (35 mg per 100ml of breath or 80 mg per 100ml of blood).
The percentage of all casualties which occurred in drink-drive collisions was the highest in Wales at 8.4% followed by England at 5.5% and Scotland at 5.0%.
Within the English regions, the casualty rates varied from 8.0% in the East Midlands to Greater London at 3.0%.
Chart 9: Percentage of casualties occurring in drink-drive collisions by country and English region, 2020
Since 2010, the proportion of casualties that occur in drink-drive collisions has been higher in Wales than in England or Scotland. Please note that the variability in figures for Scotland might be due to low underlying numbers in the estimation.
Chart 10: Percentage of casualties occurring in drink-drive collisions by country, 2011 to 2020
Casualties in drink-drive collisions by sex
In 2020, 78% of drink-drive collisions involved male drivers or riders over the legal alcohol limit. Some collisions will involve both male and female drivers over the limit, and sex is unknown for some drivers. However, males made up 71% of drivers (excluding pedal cyclists and horse riders) involved in all collisions where the sex of the driver is known.
In 2020, 69% of casualties in drink-drive collisions were male compared to 63% in all reported road collisions.
Chart 11: Drivers involved in drink-drive collisions and all reported collisions, by sex, GB: 2020
Casualties in drink-drive collisions by age
A higher proportion of casualties in drink-drive collisions were aged between 25 and 59 than in all reported collisions in 2020 (65% in drink-drive collisions compared to 59% in all collisions). The same was true for people aged 16 to 24 (24% in drink-drive collisions compared to 20% in all collisions).
Older people (aged 60+) represented a lower proportion in drink-drive collisions than collisions overall (6% in drink-drive collisions compared to 13% in all collisions). Children (under 16) also were less likely to be casualties in drink-drive collisions (4% compared to 8% in all collisions).
The percentages in the charts below do not add up to 100 as the percentages where the age of the casualty is unknown is not shown.
Chart 12: All casualties in drink-drive collisions and all reported collisions, by age group, GB: 2020
Background information
Tables published with this release
With this release, the headline table on drink-driving, RAS2001 (previously called RAS51001), has been updated with final 2020 figures. It shows collisions and casualties by severity since 1979. Estimates for 2021 are scheduled for publication in July 2023.
The tables on drink-driving are organised by topic:
-
characteristics of drink-drive collisions including by month, time of day and region
-
drivers and riders involved including by driver sex and driver age
-
drink-drive casualties by casualty type, sex and age and blood alcohol levels for those killed
Other related data sources
Breath test data for 2021 will be published in September 2022 alongside the Reported Road Casualties Great Britain: 2021 Annual Report. Breath test data for 2020 is already available.
Statistics on the results of roadside breath alcohol screening tests, administered by police forces in England and Wales in 2020, using digital breath testing devices is also published.
The devices are able to record exact breath alcohol readings and the result of individual tests, as well as reason for test, and age and sex profiles of those tested. The results are downloaded to data systems on a monthly basis and provided to the Department for Transport. These data are not provided by all police forces so are incomplete and therefore do not cover England and Wales as a whole.
The Crime Survey for England and Wales can be used to look at trends in self-reported drink driving by age, sex and frequency of alcohol consumption. Within the survey a driver is considered to be anyone who stated they had driven at least once in the past 12 months. These will not be updated this year as the survey has not taken place as a result of the COVID pandemic.
Data is also provided for self-reporting of the following:
- driving after taking medication with advice not to drive
- driving under or over the drink-drive limit
- drug driving
- diving after taking legal highs
- mobile phone use when driving
Analysis on the number of roadside tests carried out by police in England and Wales is produced by the Home Office. The figures show geographic patterns and seasonal variation. Commentary is also provided to aid the interpretation of the trends.
The motoring tool produced by the Ministry of Justice can be used to explore trends in driving convictions. The tool presents information about activity within the criminal justice system, relating to specific motoring offences. Information is provided by age, sex, court type and area, with details about the outcome of court proceedings including the fine amount and sentence length. Data on driving convictions is available.
Definitions used throughout this publication
Drink-drive collision: A reported incident on a public road in which someone is killed or injured, where at least one of the motor vehicle drivers or riders involved met one of these criteria:
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failed a roadside breath test by registering above 35 micrograms of alcohol per 100ml of breath (in England and Wales) or 22 micrograms (in Scotland)
-
refused to give a breath test specimen when requested by the police (other than when incapable of doing so for medical reasons).
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died, within 12 hours of the collision, and was subsequently found to have more than 80 milligrams of alcohol per 100ml of blood (in England and Wales) or 50 milligrams (in Scotland).
Drink-drive casualties: All road users killed or injured in drink-drive collisions.
A full list of the casualty definitions used in this release is available.
Developing drink and drug driving statistics
Frequency and timeliness of drink-drive estimates
Following user engagement we have decided to produce drink-drive estimates annually in July and to revise the estimate in the following year. In the longer term we aim to reduce the delay from the end of the year making the release more timely.
The road safety team is working to explore whether the collection of data from coroners can be improved. The aim is to improve the overall response rate and allow the publication of drink-drive estimates to be released less than 20 months after the end of the year. This approach is currently being tested; though initial findings were encouraging the COVID pandemic has impacted on data supply timescales to date due to increased coroner workloads.
The return rates for the last 4 years are as follows:
- 2017: 86%
- 2018: 87%
- 2019: 80%
- 2020: 77%
The figure for the latest year 2020 and 2019 are lower than previous years due to the COVID-19 pandemic. We aim to increase the return rate post-pandemic.
Drug-driving statistics
The road safety team has updated statistics on drug-driving (based on toxicology data for those killed in road collisions) to include 2019 data with this release.
National Statistics
National Statistics are produced to high professional standards as set out in the Code of Practice for Statistics. They undergo quality assurance reviews to ensure that they meet customer needs. The statistics were last assessed during 2013 and the report number 258, is available.
Details of Ministers and officials who receive pre-release access to these statistics up to 24 hours before release are available.
Background on legislation
The Road Safety Act 1967 introduced the first drink-driving limit in the UK, set at a maximum blood alcohol concentration of 80mg of alcohol per 100ml of blood (or the equivalent 107mg of alcohol per 100ml of urine). It became an offence to drive, attempt to drive or be in charge of a motor vehicle on a road or other public place with a BAC that exceeded the maximum prescribed legal limit. The 1967 Act also made it an offence to fail to provide a specimen for a laboratory test without reasonable excuse.
The Transport Act 1981 introduced evidential breath testing and established a maximum breath alcohol concentration of 35 micrograms of alcohol in 100ml of breath. This was implemented in 1983. Today, people are given a preliminary breath test at the roadside and then taken back to the police station for an evidential breath test.
Drink-driving legislation has been strengthened over the years, including tougher penalties for offenders which can include potentially unlimited fines, disqualification from driving, or facing imprisonment for the most serious offences.
On 5 December 2014, Scotland reduced the legal BAC limit for all drivers from 80mg/100ml of blood to 50mg/100ml. The drink drive limit introduced by the 1967 Act remains in place for England and Wales today.
Evaluation of changes to the drink-drive limit
An independent evaluation of the impact of the limit reduction in Scotland led by the University of Glasgow was published in the Lancet on 12 December 2018. This evaluation took advantage of the natural experiment created by the lowering of the legal blood alcohol limit in Scotland only and compared data on weekly road traffic collision rates and alcohol consumption (off and on sales data) between Scotland (the intervention group) and England and Wales (the control group). The study found that lowering the drink-drive limit was not associated with any reduction in total collision rates or serious and fatal collision rates, but that the change was associated with a small reduction in per-capita alcohol consumption from on trade alcohol sales.
Quality and methodology
How do final estimates differ from the provisional estimates?
The final estimates have a narrower range than the provisional estimates. This is because the final estimates are based on more toxicology reports from coroners and procurators fiscal.
The main changes between the provisional and final estimates are for fatalities. This is because the data for fatal drink-driver accidents comes predominately from the toxicology reports while non-fatal drink-drive collisions data is derived mainly from breath test data. Breath test data is complete when the provisional estimates are published.
The provisional estimate of the number of fatalities in drink-drive collisions has usually been higher than the final estimate in recent years, as the table below shows. We have decided to combine the provisional and final publications into one release in future following consultation.
Table 1: Estimated number of drink-drive fatalities at provisional and final stage, GB: 2015 to 2020
| Year | Final estimate | Provisional estimate |
|---|---|---|
| 2020 | 220 | 220 |
| 2019 | 230 | 280 |
| 2018 | 240 | 240 |
| 2017 | 250 | 290 |
| 2016 | 230 | 240 |
| 2015 | 200 | 220 |
Sampling uncertainty
Toxicology data are not available for all killed drivers or riders recorded in STATS19 and are typically available for around 60% to 70% of relevant cases.
To account for the killed drivers without a known Blood Alcohol Content (BAC), the casualties from the known cases are scaled up. The estimates are therefore based on a sample, rather than a complete count, which introduces an element of uncertainty.
Due to the nature of the data used to create these estimates, there is considerably more uncertainty in the number of fatalities and fatal collisions than any other severity level. The reason for this is that 52% of fatalities in 2020 were motor vehicle drivers themselves.
Under-reporting of road casualties
The estimates in this release are based only on those road collisions which are reported to the police. Comparisons of road accident reports with death registrations show that very few, if any, road collision fatalities are not reported to the police. However, it has long been known that a considerable proportion of non-fatal casualties are not known to the police. The data used as the basis for these statistics are therefore not a complete record of all personal injury road collisions, and this should be borne in mind when using and analysing the figures.
Changes in systems for severity reporting
Non-fatal casualties since 2016 have been affected by a large number of police forces changing their reporting systems which has had a large impact on the classification of injuries recorded. Further details are in the guide to severity adjustments.
Methodology details
A methodology note is available describing how the estimates are compiled from the sources.
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