The Leicester Mercury newspaper reports that the lights will enable the teams to catch drivers who break the speed limit on poorly or unlit roads.
The Leicester, Leicestershire and Rutland Road Safety Partnership says that, until now, a number of motorists have evaded detection because the partnership's mobile speed vans' cameras could not pick out registration plates in the dark.
The newspaper says the new infra-red equipment, which consists of three small banks of 24 bulbs mounted on the rear of the vehicles, first went on the road this week (w/b 23 January).
They are pointed in the direction the unit's camera is facing and illuminate vehicles' registration plates.
The partnership's five camera vans caught approximately 19,000 speeding drivers in 2016 by photographing their vehicles, clocking their speeds and sending penalty notices to the registered keepers.
However, partnership spokesman Jonathan Clarkson said: "The existing technology did not work particularly well in unlit streets and there is a proportion of footage the camera guys get which they can't do anything with because it is too dark.
