Background: data sources
Sources for casualty data
Surrey and Great Britain data
The Surrey stats19 data are from the local system maintained by the Police. The Great Britain comparisons use Department for Transport figures made available through the Open Government licence.
The local stats19 data are more up-to-date but the latest entries will have not been validated by DfT, so may change by a little. The information available from the two sources has some differences, for example, only the Surrey data include the stats19 contributory factors.
Where DfT data is used for the GB comparisons, the information used for Surrey is also from DfT. The numbers from the two sources differ slightly, as shown below, but this doesn’t make any significant difference to the results.
| Year | Fatal | Serious | Slight |
|---|---|---|---|
| 2008 | 0 | 0 | 0 |
| 2009 | 0 | 0 | 0 |
| 2010 | 0 | 0 | 0 |
| 2011 | 0 | 0 | -2 |
| 2012 | 0 | 1 | -2 |
| 2013 | 0 | 7 | -7 |
| 2014 | 0 | 2 | -1 |
| 2015 | 0 | 3 | 1 |
| 2016 | 0 | 1 | -2 |
| 2017 | 0 | 5 | -5 |
| 2018 | 0 | 1 | -4 |
| 2019 | 0 | 1 | -3 |
| 2020 | 0 | 0 | -1 |
| 2021 | 0 | 0 | 2 |
| 2022 | 0 | 0 | 0 |
| 2023 | 0 | 0 | 0 |
The 2018 serious injury spike in Surrey
In 2018 there was a spike in serious injuries. This was caused by a change in the method by which casualty injury severity was classified. The problem was described in the government publication, Reported road casualties in Great Britain 2018, on page 39.
Surrey Police have experienced an increase in serious collisions between 2017 and 2018. Rather than a real change, this is believed to be due to a change in the collection of the injury information in the Pronto mobile application, used by the police to collect data at the scene of the collision, to match the CRASH injury list.
DfT injury severity adjustments
DfT has introduced severity adjustment figures. For some areas of Great Britain, some casualty injury severities have been reclassified from slight to serious and vice versa, in order to account for the different methods of assessing severity that are used by different police forces. The adjustments have also been applied to figures from 2010 onwards.
The adjustment figures are not used here. Surrey’s severity classifications have not needed to be adjusted since the 2011 figures, as Surrey was the first police force to introduce an improved system of injury classification.