POLICE forces have been told to check their speed cameras and consider replacing them with a crossing, barriers or a different road layout.

New advice from the Department for Transport (Dft) urges chief constables to look again at sites where there appears to be a continuing problem of a high number of collisions.

Forces are also told to consider removing cameras at locations where the number of crashes has fallen dramatically, in case they are no longer needed.

And they should reassess so-called legacy sites - cameras that were in place before the force joined a scheme allowing it to keep the revenue - in return for increasing visibility.

The handbook of rules and guidance has been issued amid widespread opposition to cameras because of a belief that they are being used as "cash cows".

Many drivers have been upset at the camera schemes, with motoring organisations accusing scheme organisers of being more interested in revenue raising than road safety.

Since cameras were introduced across Teesside four years ago, accidents have fallen by 51 per cent, including 63 per cent in Stockton, 56 per cent in Hartlepool, 53 per cent in east Cleveland and 36 per cent in Middlesbrough.

But there has been criticism that speed camera fines raised £2m in the past year, with £3.2m raised in the Northumbria force area.

Durham is the only force in the country that has no plans to join the National Speed Camera Partnership and install visible traps.

Critics of speed cameras say its road safety record is no worse than neighbouring Northumbria, despite the absence of cameras.

Now the guidance makes it clear that cameras are only allowed where there is a history of deaths and serious injuries, and demands a review of each at least every 12 months.

A Dft spokeswoman said: "Forces must review sites regularly, because cameras are only one part of a strategy to cut deaths and serious injuries on the road.

"Where cameras are no longer appropriate, they should consider other ways, such as changing the road layout, traffic calming, or putting in a pedestrian crossing or barriers."

Yesterday's guidance emphasises that police can also use covert speed enforcement at camera sites - such as plain-clothes officers with hand-held cameras - in exceptional circumstances.