Supporting information

Sources of the data

The figures in this bulletin were largely compiled from Stats19 statistical returns made by Police Scotland. These returns cover all collisions in which a vehicle is involved that occur on roads (including footways) and that result in personal injury.

Only injury collisions reported to the police are included. The vehicle(s) involved in the collision need not be moving, and need not be in collision - for example, the returns include collisions involving people alighting from buses. Damage-only collisions, in which no people are injured, are not included in these statistics.

There could be many non-fatal injury collisions which are not reported to the police, and as a result these statistics are expected to undercount the true number of road casualties.

Stats19 forms and guidance are available on the Department for Transport website.

Future amendments to figures

Data used in this publication were extracted from Transport Scotland’s reported road collision statistical database in September 2026. Significant changes to these figures in the future are unlikely, but any late returns or further amendments will be reflected in later years’ publications.

Approach to evaluating progress against casualty reduction targets within this publication

One way of assessing progress towards the targets is to compare actual casualty numbers in each year with an indicative line that starts at the baseline figure in 2014-18 and falls, by a constant percentage reduction in each subsequent year, to the target for 2030. This is the approach previously adopted by the GB Road Safety Advisory Panel. The indicative line starts at the baseline figure in 2016 as that is the middle year of the baseline period. Other approaches could have been used: there are many ways of producing lines that indicate how casualty numbers might fall fairly steadily to the targets for 2030.

The method adopted to produce the indicative target lines shown in Figures 11, 12, 13 and 14 involves a constant percentage reduction in each year from 2016 to 2030. The resulting indicative target lines represent the percentages of the baseline averages. They are not straight lines, because of the compounding effect of constant annual percentage reductions (to two decimal places, the falls are: 4.83% p.a. for killed and seriously-injured to meet the 2030 target. For children killed and seriously injured the fall is 6.34% p.a..

Severity reporting

The classification of the severity of a collision (as “fatal”, “serious” or “slight”) is determined by the severity of the injury to the most severely injured casualty. The police usually record this information soon after the collision occurs. However, if further information becomes available which would alter the classification (for example, if a person dies within 30 days of the collision as a result of the injuries sustained in the collision) the police change the initial classification of the severity.

From the middle of 2019, Police Scotland has used the CRASH system for recording severity details of collisions. Table 4 lists the options for determining how severe an injury is. The introduction of CRASH means the severity of injuries is recorded more accurately than before and has led to an increase in the recorded number of serious injuries. Figures recorded from 2019 onwards are therefore not directly comparable with those recorded prior to the introduction of CRASH. The adjustment methodology discussed in the Introduction is an attempt to account for this and provide comparable figures.

Table 5: Classification of injury severity using the CRASH reporting system
Injury in CRASH Detailed severity Severity classification
Deceased Killed Killed
Broken neck or back Very Serious Serious
Severe head injury, unconscious Very Serious Serious
Severe chest injury, any difficulty breathing Very Serious Serious
Internal injuries Very Serious Serious
Multiple severe injuries, unconscious Very Serious Serious
Loss of arm or leg (or part) Moderately Serious Serious
Fractured pelvis or upper leg Moderately Serious Serious
Other chest injury (not bruising) Moderately Serious Serious
Deep penetrating wound Moderately Serious Serious
Multiple severe injuries, conscious Moderately Serious Serious
Fractured lower leg / ankle / foot Less Serious Serious
Fractured arm / collarbone / hand Less Serious Serious
Deep cuts / lacerations Less Serious Serious
Other head injury Less Serious Serious
Whiplash or neck pain Slight Slight
Shallow cuts / lacerations / abrasions Slight Slight
Sprains and strains Slight Slight
Bruising Slight Slight
Shock Slight Slight

Before the introduction of CRASH, the police used the following classifications for determining collision severity:

  • a fatal injury is one which causes death less than 30 days after the collision;
  • a fatal collision is an collision in which at least one person is fatally injured;
  • a serious injury is one which does not cause death less than 30 days after the collision, and which is in one (or more) of the following categories:
  • an injury for which a person is detained in hospital as an in-patient, or
  • any of the following injuries (whether or not the person is detained in hospital): fractures, concussion, internal injuries, crushings, severe cuts and lacerations, severe general shock requiring treatment, or
  • any injury causing death 30 or more days after the collision;
  • a serious collision is one in which at least one person is seriously injured, but no-one suffers a fatal injury;
  • a slight injury is any injury which is neither fatal nor serious - for example, a sprain, bruise or cut which is not judged to be severe, or slight shock requiring roadside attention;
  • a slight collision is one in which at least one person suffers “slight” injuries, but no-one is seriously injured, or fatally injured.

Over the years, improvements in vehicle design, and the provision and use of additional safety features, together with changes in the law (e.g. on the fitting and wearing of seat belts), will all have helped to reduce the severity of the injuries suffered in some collisions.

Road safety measures should also have reduced the levels of injuries sustained. For example, if traffic calming schemes reduce average speeds, people may suffer only a slight injury in collisions that previously would have taken place at higher speeds and so might previously have resulted in a serious injury.

However, it is also possible that some of the changes shown in the statistics of serious injuries and slight injuries may be due to changes in administrative practices, which may have altered the proportion of collisions categorised as serious. For example, the distinction between serious and slight injuries could be affected by factors such as changes in hospitals’ admission policies. All else being equal, the number of serious injury cases would rise, and the number of slight injury cases would fall, if it became standard procedure for a hospital to keep in overnight, for precautionary reasons, casualties with a particular type of injury.

The increase in the number of serious injury collisions in 1994 was partly attributed to a change in the health boards’ policies in admitting more child casualties for overnight observation, which in turn changed the classification of many injuries from slight to serious. The number of child casualties recorded as having serious injuries in 1994 was 35 per cent higher than in the previous year. There could also be changes in hospitals’ procedures that would reduce the numbers of serious injury cases.

Further information on road safety factors (previously contributory factors)

Contributory factors (CFs) were first included as part of the stats19 data collection in 2005. From that point, police officers attending the scene of a collision were able to select up to 6 factors that they believe contributed to the collision from a set of 77. These could be assigned to vehicles, casualties or uninjured pedestrians involved.

Contributory factors were developed to provide insight into why and how road collisions occur. Their aim was to help identify the key actions and failures that led directly to the actual impact, to aid investigation of how it might have been prevented.

As a result of the most recent stats19 review, these contributory factors were replaced by a reduced, revised set of factors known as road safety factors (RSFs). The general principles and aims remain the same as with contributory factors.

From the end of 2023, Police Scotland have been transitioning to the updated approach. According to the current stats19 specification a reporting office attending the scene of a road collision may select up to 6 road safety factors (from a list of 35) to assign to that collision. Multiple factors may be listed against any participant or vehicles in the collision.

Comparability between road safety factors and contributory factors

In some cases, the new RSFs are a direct equivalent of an existing CF (for example, R2 ‘road surface slippery due to weather’ is a direct equivalent of CF 103). In other cases, several CFs have been combined into one RSF, for example where there is little analytical benefit in having separate factors to ease the burden on reporting police officers. For example, CFs 405 (driver or rider failed to look properly) and 406 (driver or rider failed to judge other person’s path or speed) have been grouped together in B4 (ineffective observation).

This means that there is a ‘many to one’ mapping between CFs and RSFs and it is possible to recode CFs as RSFs (with some limitations). The system used by Police Scotland for recording data on injury collisions now does this recoding automatically before the data is exported to Transport Scotland. Further information on the mapping between CFs and RSFs can be found on the Department for Transport’s website.

However, despite the ability to recode CFs as RSFs, GB-level analysis by the Department for Transport has highlighted that there are differences between data recorded directly as RSFs and data that has been recoded to RSFs from CFs. This analysis found:

  • For collisions where RSFs were recorded directly, a higher number of RSFs were recorded per collision than those initially recorded using CFs then recoded.
  • The move to directly collecting RSFs results in a change in which factors are being recorded.

This led to the conclusion that there is an apparent step change in the factors that are being recorded by police forces as a result of the move to directly collecting RSFs.

Approach within this publication to road safety factor data

Given the step change between data recorded directly as RSFs and data that has been recoded to RSFs from CFs, this publication does not combine the two types of RSF data. This publication presents findings only for collisions where data was directly recorded as RSFs.

Contributory factor data, including data that has been recoded to RSFs can be requested via transtat@transport.gov.scot.

General guidance on the interpretation of road safety factors

Guidance on recording road collisions is provided in the Department for Transport’s Stats20 document which includes the following points on RSFs:

  • RSFs reflect the reporting officer’s opinion at the time of reporting, and may not be the result of extensive investigation;
  • subsequent enquiries could result in a change in the reporting officer’s opinion;
  • the RSFs are largely subjective, and depend upon the skill and experience of the investigating officer to reconstruct the events which led directly to the collision;
  • the need to exercise judgement when recording RSFs is unavoidable;
  • RSFs should be identified on the basis of evidence from sources such as witness statements and vehicle and site inspections;
  • the evidence may be of variable quality, so the officer should record very likely or possible for each RSFs;
  • when there is conflicting evidence (e.g. conflicting witness statements), the reporting officer should decide on the most credible account of the collision and base the codes on this, taking into account all other available evidence.

Regardless of the number of vehicles involved in the collision, at most six sets of RSFs data can be recorded per collision. Each set contains three pieces of information:

  • a factor which is thought to have contributed to the occurrence of the collision
  • the participant in the collision to whom the factor is related:
  • whether it was thought ‘very likely’ or just ‘possible’ this factor contributed to the occurrence of the collision

More detailed information is available in the DfT’s Stats 20 document available on DfT’s website.

Further information on wider international comparisons

The presented fatality rates presented were calculated on a per capita basis (the statistics given are rates per million population), and the countries were then listed in order of their fatality rates. In cases where two countries appear to have the same rate, the order takes account of decimal places which are not shown in the tables.

Figures were provided by the Department for Transport, which obtained the figures for foreign countries from the International Road Traffic and Accident Database (IRTAD).

In accordance with the commonly agreed international definition, most countries define a fatality as being due to a road collision if death occurs within 30 days of the collision. However, the official road collision statistics of some countries limit the fatalities to those occurring within shorter periods after the collision. The numbers of deaths, and the death rates, which appear in the IRTAD tables take account of the adjustment factors used by the Economic Commission for Europe and the European Conference of Ministers of Transport to represent standardised 30-day numbers of deaths.

Further information on collisions costs

The Department for Transport estimate the values assigned to the cost of road casualties and collisions in Great Britain, for use in cost-benefit analysis of the prevention of road casualties and collisions in road schemes.

The valuation of casualty costs calculated for Great Britain for all levels of severity are based on a willingness to pay human cost approach. This is intended to encompass all aspects of the costs of casualties including both the human cost and the direct economic cost.

The human cost covers an amount to reflect the pain, grief and suffering to the casualty, relatives and friends, and, for fatal casualties, the intrinsic loss of enjoyment of life over and above the consumption of goods and services. The economic cost covers loss of output due to injury and medical costs.

The cost of a collision also includes:

  • the cost of damage to vehicles and property; and
  • the cost of police and insurance administration.

A summary of the DfT’s latest findings can be found in table RAS4001 on the Department for Transport’s website.

Further information on drink-driving collision estimates

The Department for Transport (DfT) annually estimates the number of reported drink drive collisions: i.e. those reported injury road collisions involving drivers with illegal alcohol levels (above the current drink-drive limit of 80 milligrams (mg) of alcohol per 100 millilitres (ml) of blood or 35 micrograms per 100ml of breath in England and Wales or 50 milligrams (mg) of alcohol per 100 millilitres (ml) of blood or 22 micrograms per 100ml of breath in Scotland from the 5th December 2014).

DfT published GB figures in July 2026. Scotland estimates are presented in Reported Road Casualties GB Table RAS 2013 which was updated with 2024 data in July 2026. Because of the uncertainty involved figures are rounded to the nearest ten.

The DfT’s publication outlines the estimation methods in detail. It draws on Stats 19 reported road collision data (where motor vehicle drivers or riders failed or refused to provide a sample of breath) and Procurators Fiscal (and Coroners in England and Wales) data on blood alcohol levels of drivers who died within 12 hours of being injured in a road collision. The estimates include allowances for the numbers of cases where drivers or riders are not breath tested due to the collision being a hit and run collision. Drink drive casualties are defined here as any casualties resulting from a drink drive collision.

Estimates for 2025 are not yet available because of the timing of the provision of the data regarding blood alcohol levels of fatalities from Procurators Fiscal (and Coroners in England and Wales) to DfT. At this stage the sample of 2025 data is insufficient to allow a breakdown by country.

There are no estimates for Scotland of the number of alcohol-related injury road collisions which involve legal alcohol levels (i.e. alcohol levels up to and including the current drink-drive limit of 80mg of alcohol per 100ml of blood), nor are there any estimates for Scotland of the numbers of non-injury (damage only) road collisions involving illegal alcohol levels.

The figures here differ from the number of drivers with positive (or refused) breath tests. While the Police aim to breath test all drivers involved in an collision this isn’t always possible (e.g. hit and run drivers or due to severity of casualty). Recently, just over a half of motorists involved in injury road collisions in Scotland have been breath tested.

Access to data

Almost all of the data collected for this statistical bulletin are available as part of a GB-wide dataset available on data.gov.uk

Further detail be made available on request, subject to consideration of legal and ethical factors. Please contact Transtat@transport.gov.scot for further information.