This information is not collected centrally.
Information on the number and purposes of vehicle stops carried out by the police is not collected centrally. Information on the number of screening breath tests carried out by the police and on the number of motoring offences detected is contained in the annual publication "Motoring Offences and Breath Test Statistics, England and Wales" available in the Library and at:
www.homeoffice.gov.uk/rds/pubsstatistical.html