Effects of speed cameras

All safety devices can have both positive benefits and negative side effects.
This page suggests how collisions might change, and then looks at actual examples.

Effects of speed cameras may be closely linked to speed limits.

If speed limits are not set at a reasonable safe speed for most conditions, are poorly signed, or change frequently, then the effects of speed cameras may be much greater.

Possible positive benefits of speed cameras.

Speed cameras can prevent collisions where:

1. a motorist was exceeding the speed limit before the collision
2. and that motorist could have been identified and prosecuted using the registered keeper details.

Possible negative side effects of speed cameras.

In the following examples, the closest contributory factors are shown so that their relative importance can be compared to the 1400 KSI collisions that involve speeding.

1. Motorists may brake suddenly near to speed cameras, or even where there aren’t any if they see what could be a camera up ahead. Even motorists not speeding may brake suddenly if they are not aware of the current speed limit or do not know their exact speed.
   • 906 involved “Sudden braking”.
2. When approaching speed cameras, motorists may look down at their speedometer at about the same time as the vehicle in front brakes. Also, even where there are no cameras, motorists may be looking for speed limit signs and checking their speedometer more frequently. This increases the possibility of looking away just as an accident situation develops, such as a child running across the road. Such distractions could lead to motorists taking longer to react to hazards and swerving, or losing control.
   • 4167 involved “Loss of control”.
   • 888 involved “Swerved”.
   • 440 involved “Distraction in vehicle”.
3. In terms of speed, motorists drive safely by slowing down where there are many hazards and speeding up where there are fewer. By preventing speeding up where it is safe, speed cameras encourage driving at a more uniform speed close to the speed limit. This would be slower where there are few hazards, but could also be faster where there are more. That could lead to “Travelling too fast for conditions”.
   • 1,780 involved “Travelling too fast for conditions” (defined as within the speed limit).
4. Speed cameras take £6.8 million out of the economy every year just in Thames Valley alone. For the same cost to society, Thames Valley Police could have 114 more police officers with 114 more Police cars (data). Speed cameras mean fewer traffic police and that may lead to an increase in drink driving.
   • 1252 involved “Impaired by alcohol”.
5. Motorists attention levels may be closely linked to their perception of speed (ie slow may feel boring). Slower speeds enforced by speed cameras may reduce attention levels leading to failure to notice other road users.
   • 6,387 involved “Failed to look properly”.
6. People pay greatest attention where danger is perceived. If speed cameras and slower speeds make roads “feel safe” then less care might be taken, particularly by pedestrians and cyclists. Slower cars are also quieter and lack of noise can be such a safety issue that electric cars can have artificial engine noises to alert pedestrians.
   • 2,980 involved “Pedestrian failed to look properly”.
7. Slower speeds enforced by cameras mean journeys can take longer so increase the risk of tiredness or falling asleep.
   • 371 involved “Fatigue”.

Motorcyclists may suffer a particular set of risks from speed cameras.

Motorcyclists are far more likely to be killed or injured than vehicle occupants. After hitting a motorcyclist, drivers often say “Sorry Mate, I Didn’t See You” (known as SMIDSY accidents). This might be classed as “Failed to look properly” and it’s been the largest factor in KSI collisions by some margin every year. This means that, as well as ensuring they do not cause a collision themselves, motorcyclists have to avoid collisions that drivers might cause. As a result, motorcyclists can require greater changes of road position and speed than other road users.

Eg, it can be more difficult for motorcyclists to monitor traffic behind them (due to the helmet restricting visibility and mirrors being set for a particular riding position, etc) therefore it may sometimes be safer to ride at a higher speed in order to minimise the danger of drivers behind following too close or not paying attention.

Also, it may be less safe for motorcyclists to pull away from traffic lights at a slower speed if that results in them being surrounded by other vehicles. It may be safer to use a higher speed to create (and then maintain) a gap to the group of vehicles released by the traffic lights. By doing this, motorcyclists can spend more of their journey clear of the vehicles that pose a threat to their safety.

Also, where a vehicle is approaching from a side road, the motorcyclist on the main road may have 3 options:

1. Slow down and risk the car behind hitting them.
2. Continue at the same speed and risk the car from the side road hitting them.
3. Speed up in order to pass the junction before the driver reaches it.

Examples of positive benefits:

There are none, apparently. I tried to find examples of collisions that could have been prevented by a speed camera. I asked the Police, the speed camera operators, the Department for Transport and local council road safety departments. All said that none of the collisions they have on record would have been prevented had a speed camera been at the location. Even the collisions that led to a camera being deployed would not have been prevented by the camera. They say collisions tend to involve several factors and the benefits of speed cameras are in general safety, not in specific examples.

This is surprising. All these organisations have presented many examples where other devices would have prevented collisions or injuries (such as seat-belts, ABS brakes, air-bags, collapsible signs, breathalysers, helmets etc).

• Speed cameras must be unique as the only safety device for which there are no examples of positive benefit.

Examples of negative side effects:

Collisions have occurred where speed cameras are implicated as a contributory factor. For example, the BBC showed videos taken from speed camera vans where 2 collisions appear to have been triggered by the speed cameras (video).

And there have even been fatalities including:

• A driver who was “unlikely to have even been speeding” was killed after losing control approaching a gatso speed camera (The DailyRecord or ScreenShot).
• A pedestrian was killed after a driver may have been distracted by a Gatso speed camera, according to the Coroner and the Police accident investigator (Manchester Evening News or ScreenShot).
• A motorcyclist was killed when he saw a mobile speed camera van, braked and lost control (The Daily Echo or ScreenShot).