Critics claim speed cameras are used to make money

At the moment, cameras can only be sited in places where there has been a history of deaths and injuries.

But senior police officers want the freedom to put speed traps on longer stretches of road around accident sites, with 20km suggested.

The issue of speed cameras is always controversial, with critics claiming they are used to make money.

Government figures show there were more than 3,500 deaths on Britain's roads in 2003, up from 3,431 in the previous year.

At the same time the number of speed camera fines reached two million.

The Association of Chief Police Officers proposition on mobile cameras is being discussed by a committee led by officials from the Department of Transport.

If approved, they will be included in new guidelines issued later in the year.

Richard Brunstrom, head of road policing for the Association of Chief Police Officers, told the Times: "We have a particular problem with motorcyclists slowing down for the cameras but then speeding up and dying on the next corner.

"We need to keep people's speed down along the whole stretch of road."

He acknowledged the death rate on British roads had not been cut despite there being around 6,000 cameras already in use.

"We have got cameras at almost all the identifiable casualty hotspots and yet deaths haven't gone down because they are happening elsewhere."

The RAC Foundation said speed camera rules should be more flexible, but that police should also look into other road safety measures.