Car Crime Census: Methodology

Published 16 August 2013

The HonestJohn.co.uk Car Crime Census is the first ever detailed analysis of car crime. We’ve studied more than 500,000 car crime records, between October 2011 to September 2012, to pinpoint crime down to postcode and street. The census has also calculated average offences per 10,000 vehicles and taken into account the higher levels of crime in urban areas.

During the census we wrote to each of the 51 forces police forces in England, Scotland and Wales for 12 months of data on vehicle crime under the Freedom of Information Act.

The information we requested included the make and model of the vehicle affected by each offence. It also included the type of offence: whether the crime was the theft of the vehicle, theft of property from the vehicle, criminal damage, and so on.

Of the 51 forces we asked, 42 replied with data and 29 of these included a make and model. All but one included details on the type of offence.

The offences that were considered to be covered by the term 'vehicle crime' differed slightly from force to force, and therefore direct comparisons between the statistics for offences by manufacturer and by type for different forces should not be made.

To provide a finer grained geographic breakdown of vehicle crime we have also used 12 months of data from Police.uk, which provides national grid coordinates for vehicle crime within England and Wales.

In processing the data, we have made use of postcode and boundary data from the Ordnance Survey, vehicle licencing statistics from the Department for Transport, and data on administrative geography from the Office of National Statistics.

To ensure we provide a balanced picture of car crime at a national level, we have used the equivilent of a 'per capita' figure, comparing the crime rate to the number of vehicles registered. Traditionally, crime surveys have compared crime to the number of people living in each district. We’ve differed from this method because not everyone owns a vehicle and comparing the crime rate to the number of registered vehicles provide a much more accurate representation of car crime in the UK.