In British slang, a "jam sandwich" or "jam butty" is a police car with a red stripe applied to the side.
The term "jam sandwich" came into common use in the 1970s, as police cars changed from block colour schemes such as the blue and white "panda car" to broad fluorescent sidestriped liveries on white or grey base paint. A thin amber sidestripe, fitted using fluorescent tape and vinyl sheeting, was first applied to vehicles of the East Sussex Constabulary in 1965, introduced on the recommendation of Chief Constable George Terry. Some forces, such as the Hertfordshire Constabulary, would later introduce a blue border around the sidestripe.[1] This livery scheme was seen as reminiscent of jam sandwiched between two slices of white bread, hence the name. The slang was popularised on TV shows such as The Bill, The Sweeney and Minder; as well as spreading through the use of CB radio.
The "jam sandwich" first came into use with London's Metropolitan Police in 1978, first applied on a fleet of new high-performance Rover SD1 traffic cars.[2] Marked vehicles were initially finished in base white paint with "jam sandwich" livery applied on each side, however the base colour was changed to silver from 2002 to help improve a vehicle's resale value when it was retired from police use.[3]
The "jam sandwich" livery on police vehicles across the United Kingdom has today been replaced by Battenburg markings, first introduced in 1998 on the recommendation that the livery makes the vehicle easily identifiable by oncoming drivers as a police vehicle from at least . As part of a move to promote "High Visibility Policing" in conjunction with the use of force logos, by 2003, 76% of forces had begun adopting the markings as well as a "half battenburg" variant for urban and suburban patrols.[4] This livery began to be introduced on new vehicles delivered to the Metropolitan Police from November 2012.[5] [6] [7]
However, a handful of older vehicles are still marked in "jam sandwich" livery in some police forces in the United Kingdom. In the Metropolitan Police, the term 'jam sandwich' now colloquially refers to the car's livery only, as worn by remaining older vehicles and public order carriers that have not yet been replaced.