A Road Crime Unit or Pro Active Unit is a police unit derived from traffic policing departments in the United Kingdom. Certain forces have established such units with a mandate to pro-actively target certain crime offences (robbery, burglary etc.) where there is likely to be a link to the use of a motor vehicle in the commission of the crime.
A popular example of this is Road Wars, a British reality TV series that follows police officers from the Pro Active Units from Thames Valley Police and Devon and Cornwall Police.
References
Road Crime Unit Wikipedia(Text) CC BY-SA