The Big Question: Are speed cameras really the best way to improve road safety?

Why are we asking this question now?

Some local authorities are considering replacing their speed bumps on side streets with cameras. These cameras would be able to measure the average speed of motorists driving through a neighbourhood and, it is said, make the streets safe without the objectionable features of bumps: wear and tear on cars, slowing down emergency vehicles, and encouraging motorists to speed up between the bumps, thus generating noise and pollution.

How long have speed cameras been used?

Speed "traps" have come a long way since 1901, when Richard Moffat Ford became the first person in Britain to be prosecuted. He was caught by a constable hiding in a hedge with a stopwatch. Speed cameras, as we now know them, were introduced in 1992, but the numbers began to rise dramatically from 2000 onwards, after the Government allowed authorities in eight areas to recover the cost of operating them from fines resulting from enforcement. In 2001 legislation was introduced that allowed the system to be extended to other areas

What do the doubters say?

Opponents of cameras argue that "speed doesn't kill". The British Association of Drivers contends that the present approach means we are encouraging "legal driving, rather than safe driving". Mark McArthur-Christie, of the association, argues there should be far more emphasis on training drivers than penalising them.

One estimate relating to County Durham showed that only 3 per cent of collisions involved cars that were exceeding the speed limit. Fatigue and failure to look out for oncoming vehicles when turning right were thought to be the main causes of accidents.

Paul Smith, of Safe Speed, believes cars can be driven "perfectly safely without reference to a speedometer". He points out that the police routinely train their drivers on public roads at speeds of more than 125mph. "They do not do this lightly," he says. "They do it because they know full well that such speeds, in the right circumstances, are perfectly safe."

Does speed really matter so much?

The bulk of road-safety research overwhelmingly supports the link between speed and the frequency and severity of crashes. Most experts subscribe to the assertion that "inappropriate" speed is a major contributor to at least one-third of all crashes and is therefore is the single most important factor.

The Parliamentary Advisory Council for Transport Safety says studies based on the crash history of 300 sections of road, 2 million measurements of speed and the self-reported crash history of 10,000 drivers, conclusively demonstrated the correlation between speed and crash frequency.

Speed-camera enthusiasts point out that simple physics dictates that the severity of injuries increase with speed. The road safety campaigners Brake point out that if a car hits a pedestrian at 35mph, they are twice as likely to die as if they were hit at 30mph. Environmentalists add another argument to the health and safety case for cameras. They point out that higher speeds mean more consumption of energy and greater carbon emissions. They believe everyone should drive more slowly at all times.

Have cameras reduced speeding?

A report commissioned by the Government showed speeds at cameras sites have been cut by 6 per cent. Where fixed cameras are used, there has been a 70 per cent reduction in vehicles breaking the limit. Overall, the proportion of vehicles speeding "excessively" - 15mph over the limit - fell by 91 per cent at fixed-camera sites.

Have they reduced casualties?

The Department for Transport says that even allowing for the long-term downward trend, there was a 22 per cent reduction in injuries at sites where cameras were introduced; 42 per cent fewer people were killed or seriously injured. At camera sites there was a reduction of more than 100 fatalities a year - 32 per cent fewer.

How unpopular are speed cameras?

A recent poll in The Daily Telegraph concluded that seven out of 10 motorists believe they are mainly devices to raise money, and do little to reduce crashes. Some polls have found that cameras are popular and others that they are not. A "poll of polls" compiled by the pro-camera group Transport 2000 - based on six surveys - shows that backing for cameras averages 74 per cent. A Department for Transport survey found that more than 80 per cent of people living in the original pilot areas agreed that "cameras are meant to encourage drivers to keep the speed limit, not to punish them".

Are they just a ruse to raise money for the Treasury?

Strict Treasury rules mean that any money from fines is returned to the partnerships and can be spent only on the operational costs of their camera network, including new cameras, where the need can be identified. All remaining money goes to the Treasury and does not stay with the partnership.

Will they be installed in residential areas?

Trials of the new cameras, which measure average speeds rather than snapshots of a short patch, have taken place in Camden, north London, and Belfast. No tickets have been issued yet, but the technology has proved to be reliable. So far the specs cameras have been installed at only two sites, both on motorways at roadworks. But their use is expected to spread.

The Department for Transport contends that councils will be loath to use the "specs cameras" because they are far more expensive than the humps, or "sleeping policemen", as they used to be called, which are normally used to slow traffic in side streets. It is possible that some councils may use them in "accident black spots".

Are speed cameras a good thing?

Yes...

* They have reduced speeds and lowered the number of accidents wherever they have been installed

* The lower the speed at which an accident occurs, the less the chance that an accident will result in fatal injuries

* Their presence simply ensures that speed limits are observed

No...

* Bad driving and fatigue are the principal causes of accidents, not excessive speeds

* Motorists slowing down for cameras are in fact themselves a cause of accidents

* They are really just a form of government stealth tax