Government sources confirm that speed cameras are to be made clearly visible in a move to reassure motorists that the issue is "accident prevention rather than revenue raising".

The Home Office and Department for Transport, Local Government and the Regions have been in discussions about how to make the controversial cameras visible to motorists. New brighter markings for cameras are set to be announced with the extension of a pilot scheme allowing eight police forces to retain a proportion of speeding fines to be reinvested in road safety measures.

Ministers have been concerned that the low visibility of the cameras - currently most are battleship grey - will lead to increasing motorist resentment as "hypothecation" schemes are extended and the number of fines rockets.

In Northamptonshire - one of the pilot schemes - the number of tickets issued to motorists soared from 4500 in 1999/2000 to 84,000 in 2000/2001 as the local police force invested in new cameras that were linked to revenue raising.

The government hopes to reinforce the message that the cameras bring safety improvements. A Yorkshire scheme saw cameras marked bright orange to encourage drivers to slow down, an initiative said to be favoured as a model by the government.