Guidance

Reported road casualties in Great Britain: notes, definitions, symbols and conventions

Published 29 September 2022

Background notes

The statistics refer to personal injury collisions (alternatively, accidents) on public roads (including footways) which become known to the police within 30 days. Damage-only collisions, with no human casualties, and collisions on private roads or car parks are not included in the statistics.

The data are collected by police at the scene of a collision or in some cases reported by a member of the public at a police station or online. Some 50 data items are collected for each collision, including the time and location of the collision, the types of vehicles involved and what they were doing at the time of the collision, and some information on the drivers and casualties involved. The data are processed and then passed by the police (or their agent) to the Department for final checking and analysis.

The form used to collect the statistics (STATS19) and instructions containing definitions to complete the form (STATS20) are published by the DfT, the Scottish Government and the Welsh Assembly Government in the forms and guidance page. More general guidance on the quality of these statistics is also available.

As noted above, statistics on road safety in Great Britain are mostly based on collisions reported to the police via the STATS19 system. Comparisons with death registration statistics 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, as hospital, survey and compensation claims data all indicate a higher number of casualties than are reported via STATS19.

The department produces an annual ‘best estimate’ of the total number of road casualties in Great Britain each year, including those not reported to police. This is derived primarily from National Travel Survey (NTS) data which, from 2013, is based on an England only resident sample. The latest such estimates are provided in the data tables with links to further information on how they have been compiled.

When using the STATS19 data, it should therefore be appreciated that it is not a complete record of all injury collisions. However, STATS19 data remains the most detailed, complete and reliable single source of information on road casualties covering the whole of Great Britain, in particular for monitoring trends over time.

Road safety data definitions

Adult Persons aged 16 years and over (except where otherwise stated).

Agricultural vehicles Mainly comprises agricultural tractors (whether or not towing) but also includes mobile excavators and front dumpers.

A(M) roads Motorway standard roads that are not titled as ‘motorways’, for example the A1(M).

Built-up roads Roads with speed limits of 40 mph or less (ignoring temporary limits).

Buses and coaches Buses or coaches equipped to carry 17 or more passengers, regardless of use.

Cars Includes taxis, estate cars, three and four wheel cars, and minibuses, except where otherwise stated. Also includes motor caravans prior to 1999.

Casualty A person killed or injured in an collision. Casualties are sub-divided into killed, seriously injured and slightly injured.

Children Persons under 16 years of age (except where otherwise stated).

Darkness From half an hour after sunset to half an hour before sunrise.

Daylight All times other than darkness.

DfT Department for Transport.

Drivers Persons in control of vehicles other than pedal cycles, motorcycles and ridden animals (see riders). Other occupants of vehicles are passengers.

Failed breath test This includes

  • drivers or riders whose test indicated that they had above the legal limit of alcohol in their blood to drive

  • drivers who failed to provide a specimen of breath

  • drivers who refused to provide a specimen of breath

Fatal collision A collision in which at least one person is killed.

Goods vehicles These include tankers, tractor units without their semi-trailers, trailers, articulated vehicles and pick-up trucks. Goods vehicles are further divided into two groups according to vehicle weight (see heavy goods vehicles and light goods vehicles).

Heavy goods vehicles (HGV) Goods vehicles with a maximum permissible gross vehicle weight of over 3.5 tonnes.

Injury collision A collision involving human injury or death.

Killed Human casualties who sustained injuries which caused death less than 30 days (before 1954, about two months) after the collision. Confirmed suicides are excluded.

KSI Killed or seriously injured.

Light goods vehicles Goods vehicles, mainly vans (including car derived vans), not over 3.5 tonnes maximum permissible gross vehicle weight.

Motorcycles Two-wheel motor vehicles, including mopeds, motor scooters and motor cycle combinations.

Motorways Motorway and A(M) roads.

Mobility scooter A powered wheelchair or scooter with a maximum weight of 150kg before loaded and a maximum speed of 8mph.

Non-built-up roads Roads with speed limits over 40 mph. Motorway collisions are shown separately and are excluded from the totals for non-built-up roads.

Other roads All B, C and unclassified roads, unless otherwise noted.

Other vehicles Other vehicles include ambulances, fire engines, trams, refuse vehicles, road rollers, agricultural vehicles, excavators, mobile cranes, mobility scooters and motorised wheelchairs for example, except where otherwise stated. Also included are non-motorised vehicles, including those drawn by an animal, ridden horse, wheelchairs without a motor, street barrows for example, except where otherwise stated. In certain tables “other vehicles” may also include buses and coaches and/or goods vehicles, as indicated in a footnote.

Passengers Occupants of vehicles, other than the person in control (the driver or rider). Includes pillion passengers.

Pedal cycles Includes tandems, tricycles and toy cycles ridden on the carriageway. From 1983, the definition includes a small number of cycles and tricycles with battery assistance with a maximum speed of 15 mph.

Pedal cyclists Riders of pedal cycles, including any passengers.

Pedestrians Includes

  • children riding toy cycles on the footway

  • persons pushing bicycles

  • persons pushing or pulling other vehicles or operating pedestrian-controlled vehicles

  • persons leading or herding animals

  • children in prams or buggies

  • people who alight safely from vehicles and are subsequently injured

Riders Persons in control of pedal cycles, motorcycles or ridden animals. Other occupants of these vehicles are passengers.

Road users Pedestrians and vehicle riders, drivers and passengers.

Rural roads Major roads and minor roads outside urban areas and having a population of less than 10,000.

Serious collision One in which at least one person is seriously injured but no person (other than a confirmed suicide) is killed.

Serious injury An injury for which a person is detained in hospital as an “in-patient”, or any of the following injuries whether or not they are detained in hospital: fractures, concussion, internal injuries, crushings, burns (excluding friction burns), severe cuts, severe general shock requiring medical treatment and injuries causing death 30 or more days after the collision.

An injured casualty is recorded as seriously or slightly injured by the police on the basis of information available within a short time of the collision. This generally will not reflect the results of a medical examination, but may be influenced according to whether the casualty is hospitalised or not. Hospitalisation procedures will vary regionally.

Severity Severity can refer to collision severity or casualty severity. Severity of a casualty refers to whether the casualty was killed, seriously injured or slightly injured. Severity of a collision refers to the severity of the most severely injured casualty (either fatal, serious or slight).

Slight collision One in which at least one person is slightly injured but no person is killed or seriously injured.

Slight injury An injury of a minor character such as a sprain (including neck whiplash injury), bruise or cut which are not judged to be severe, or slight shock requiring roadside attention. This definition includes injuries not requiring medical treatment.

Speed limits Permanent speed limits applicable to the roadway.

Taxi Any vehicle operating as a hackney carriage, regardless of construction, and bearing the appropriate district council or local authority hackney carriage plates. Also includes private hire cars.

Users of a vehicle All occupants, such as driver (or rider) and passengers, including persons injured while boarding or alighting from the vehicle.

Urban roads Urban roads are those within an area of population of 10,000 or more. Tables produced for years prior to 2017 are based on the 2001 Communities and Local Government definition of Urban Settlements. Tables produced from 2017 are based on the 2011 census data that uses a revised 2001 Communities and Local Government classification.

Vehicles Vehicles (except taxis) are classified according to their structural type and not according to their employment or category of licence at the time of a collision.

Vehicles involved in collisions Includes

  • vehicles whose drivers or passengers are injured

  • vehicles which hit and injure a pedestrian or another vehicle whose driver or passengers are injured

  • any vehicle that contributes to the collision

Vehicles which collide, after the initial injury-based collision, are not included unless they aggravate the degree of injury or lead to further casualties. Pedal cycles ridden on the footway are included.

Statistical terms

Aggregate data Data collected from multiple sources which is then integrated into a summary.

Confidence limits There is some uncertainty in the data. The confidence limits are the highest and lowest data points that we are confident that the true value falls between.

Intrinsic trend The true trend that we would measure if we had 100% accuracy in our measurement and capture every casualty without error or uncertainty.

Statistical significance 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 (in this case 95% confident) that the difference between the 2 figures is the result of a genuine change, rather than being a product of chance. 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 95% level of confidence.

Symbols and conventions used

Rounding of figures In tables where figures have been rounded, there may be a slight discrepancy between the sum of the constituent items and the total as shown.

Symbols The following symbols have been used throughout these statistics:

  • 0 = nil or negligible (less than half the final digit shown)

  • Conversion factor: 1 mile = 1.6093 kilometres

  • Billion = One thousand million = 1000,000,000 = 10 to the power 9

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Road safety statistics