Speed Camera Effects

Road deaths in the UK dropped MORE in a single year from 1992 to 1993 than they did from 1993 to 2002

Summarizing the Safe Speed view...

Highlighting the dangers


We have gathered together on this page our best data and analysis of the effects of speed cameras on road safety in the UK. We don't have to cherry pick facts, areas or years to tell our story. The data is clear and plentiful. The arguments are based on knowledge of safe driving and the clear principles that gave us the safest roads in the world. 

Weapons of mass distraction...

[image copyright © 2003 www.safespeed.org.uk]

Effects on road fatalities

There has been a very long established beneficial trend in the UK fatal accident rate. It dropped from 94.46 fatals per billion vehicle kilometres in 1950 to 9.25 fatals per billion vehicle kilometres in 1993. Since 1993 that regular and reliable annual reduction (equivalent to 5.26% per annum) has declined to near zero. The red line on the graph (actual official road fatalities for England and Wales) shows what has really happened. 2002 was the highest figure (3,127) since 1997 (3,222) 

From 1978 until 1993 the fatality rate trend was better (equivalent to 6.81% per annum). The yellow dashed line on the graph above shows how deaths would have fallen if this trend had continued and is properly corrected for the negative effect of increased traffic.

If speed cameras had shown a benefit we would have expected to see a larger improvement in the fatality rate. The blue line (also corrected for traffic volumes) shows an example of what might have happened if cameras had saved lives.

The green line shows actual official home office convictions by speed camera from 1990 (0) through the first 290 speed camera convictions in 1992 through to an amazing 1,014,600 speed camera convictions in 2001. Figures for 2002 are not yet available but we expect more than 1.3 million to be announced shortly (shown dashed).

So it's clear that during the period of speed camera growth the roads have not become safer. If speed cameras worked and "some other factor" caused the loss of trend it would have to be absolutely enormous to account for the difference between the blue line (possible camera benefit) and the red (actual data).

Note carefully how things have changed:

year national road deaths speed camera convictions (England and Wales) national traffic (billion vehicle km) national fatality rate (killed per billion vehicle km)
1998 3,421 403,800 459.58 7.44
2002 3,431 1,300,000 (estimated) 485.95 7.06
2002 compared with 1998 100.3% 322% 106% 94.9%
1988 5,052 - 375.70 13.45
1992 4,229 290 421.5 10.03
1992 compared with 1988 83.7% - 112% 74.6%
1978 6,831 - 256.51 26.63
1982 5,934 - 284.46 20.86
1982 compared with 1978 86.8% - 110.9% 78.3%

This is no trick. We've not selected funny periods (although road safety did do very well from 1990 to 1993 because of the "ERM slump"). We really have completely failed to maintain our road safety improvement over the last decade or so.

We can't prove that the loss of trend has been caused by speed cameras (and the policies which support them), but despite extensive investigations, we have found nothing else that fits the pattern of loss of trend. We offer straightforward logical mechanisms explaining how it is possible.

At the very least, the evidence is compelling enough to call an immediate halt to camera proliferation and undertake a proper scientific investigation.

We are having a road safety disaster, but the powers that be have yet to face up to it. Instead they trot out a series of tired old lies based of over-simplified reasoning, inadequate data and misleading statistics. You can read about the lies (here).

Fatal accident rate

The red line shows the actual fatal accident rate data from official sources. The yellow line accurately represents the 1978 to 1993 beneficial trend (properly corrected for traffic volumes). If that trend had continued, more than 5,500 people would still be alive now that have died on Britain's roads since 1993. (calculated to end August 2003). The extent of the change is now running at about 1,200 lives each year and increasing.

We have been reporting this effect for over a year. See: (fatality)

Having looked very carefully for possible causes of the loss of trend we have only found one change which is big enough, ugly enough, ongoing enough and timed correctly to account for it. Try these factors:

factor basis for dismissal Corroboration
Growth of mobile phone driving Started in the 80s. RoSPA found only 19 associated deaths over a 12 year period. - we're looking for more than 1,200 a year. The coroner's courts would notice. The effect does not exist in Germany, France, Italy and others. They have a growth of mobile phone driving too don't they?
Growth of 4x4 vehicles Started in the 70s. We would need 1/3 rd of fatal accidents to involve a 4x4 - it would be obvious to Police and journalists that this was happening. American research made 4x4 vehicles about 3% less safe overall, but they were better in many accidents as the height and weight protected their occupants.
Traffic has saturated There have been pockets of saturation since the 1930s. Granted we have more pockets of saturation now, but the spread has been steady.  You can't get a step change in 1993 out of any model of traffic growth. The pattern and spread of congestion is steady.
Too many boy racers We have always had boy racers. They were not invented in 1993. Boy racers could quite possibly be responsible for over a quarter of fatalities, But it would be absurd to suggest that they were responsible for none before 1992.

So the real factor that we believe has caused this deadly loss of trend was a change in road safety policy. In 1993 we launched speed cameras on the public and backed them with "speed kills" and "slow down" messages. Since then it's been growing and growing. This policy has had a range of knock on effects:

  • The Police now leave much of their their job on the roads to "PC Gatso".
  • Public fear of traffic (and especially "speeding drivers") has increased considerably (this probably does provide a perverse road safety benefit - but it must be swamped because it simply isn't there in national figures for all road fatalities). We note that pedestrian deaths on British roads are still falling (offset by rises elsewhere of course). These saved lives may well be due to increasing pedestrian fear of traffic. If they were due to drivers slowing, then we would have to expect other groups to benefit, but this simply isn't happening.
  • Millions of responsible motorists began to pay more attention to speed limit, speed enforcement and speedo reading. Since they only have a finite amount of attention to give, this must mean they they now pay less attention to "something else".  We are sure that on a significant proportion of occasions that "something else" includes much more immediate and vital safety factors - perhaps a dangerous situation developing ahead.
  • Millions of different, (and less skilled) motorists have received the message that keeping to the speed limit is their primary duty to road safety. It's frightening to imagine a driver steaming into danger at 29 mph convinced that his speed must be safe.
  • Responsibility for safe speed setting is being removed from drivers. Instead they must drive to standard speeds posted by local authorities and others. But responsibility is a core value of safe driving. Erode drivers responsibilities and their performance in terms of setting safe speeds and avoiding crashes is highly likely to worsen.
There are other effects, (we maintain a list (click here)), but this group of five are probably the most important.

None of these effects have been the subject of proper scientific research. Until they are we won't know for sure which prove to be the most important on the road. But the 1993 shift in road safety policy is the only factor we can identify which could reasonably be blamed for the loss of trend in the fatal accident rate. It follows that there would have to be a mechanism whereby such a policy change could affect the fatality rate for the worse. These five factors offer just such a mechanism, and they are all plausible.

Factors affecting road safety

We've created an experimental model of UK road safety. See (factors). In order to make fatalities behave as they have done, "something" on the "input side" must change - drastically - by about 6% for the worse in about 1993.

We know that there are large and ongoing safety benefits coming from vehicle safety improvements, road engineering improvements (including especially black spot treatments and bypasses) and we know that improvements in medical care improve the chances of survival after a crash. These three factors together have always swamped the growth in traffic to deliver much safer roads with large and regular improvements in the fatality rate. But this does not happen any more.

What's the factor that got worse suddenly in about 1993? It's drivers. We're not as good at avoiding big crashes any more. We're being fed false safety messages and we're being distracted from real road safety. Read on.

Excessive speed accidents

We were very interested to come across (this document) regarding road safety in Warwickshire. It included the only data we have seen about changing patterns of accident causation over time. Figure 15 in that document shows the number of times "excessive speed" has been recorded as an accident causation factor by year since 1995. Over that period there has been a massive growth in speed cameras, so we'd expect to find fewer accidents caused by excessive speed in recent years. But not one bit of it, in fact the opposite is true. As you can see in the graph above.

New: We decided to write to the Chief Constable of Warwickshire and ask him what he thinks about the trend. (click here)

Could speed cameras increase the number or the proportion of excessive speed accidents?

Absolutely. That's exactly what we expect - exactly what we have been warning would happen. Drivers are now paying less attention to the right things and they are less good at reducing speed when necessary. Read on.

How do people have excessive speed accidents?

Method 1 - nutters, cops and criminals - no change due to speed kills policy

We will always have a few people using the roads without normal regard for the safety of others. Sometimes a genuine life or death mission will cause a Police driver to exceed safe thresholds. Sometimes an escaping criminal will risk his own life and other peoples' lives in an attempt to get away. Sometimes a normal person will abandon all caution because of a serious personal problem. And sometimes young nutters think they are driving gods and can get away with anything. People in these groups may use very high speeds and may have terrible crashes. But they won't respond to speed limit enforcement by camera - they have other priorities and speeding tickets are not a consideration. Many truly dangerous very high speed accidents come from this group.

Method 2 - carelessness, inattention or hazard perception failure - worse due to speed kills policy

The majority of excessive speed accidents probably fall into this group. It's not so much a case of driving too fast - more a case of failing to slow down when necessary. When we encounter road hazards - and it happens many times during each drive - we normally respond by reducing speed to negotiate the hazard safely. If we fail to recognize the hazard (or recognize it late because we were inattentive) we may not have enough time left to slow down to a safe speed. This sort of accident is clearly a serious road safety issue, but we think more speed enforcement will tend to make this sort of accident more common. The major factor here is that these apparent excessive speed accidents actually spring out of problems with driver attention. More speed enforcement is highly likely to reduce average driver attention and exacerbate this group of excessive speed accidents. 

Method 3 - judgement failure - some worse,  some better due to speed kills policy

Think of someone that misjudges the severity of a bend, enters it too fast and crashes. Since in most cases this sort of misjudgement arises out of adjusted speed rather than free travelling speed it's unlikely that speed enforcement could make much difference. There might be a narrow range of hazards where the maximum safe speed is around or just over the speed limit where enforcement might provide a benefit. But the more we try to avoid drivers making this sort of judgement error, the less practice they get, and the more useless they become. Call it the nanny effect - too much protection makes us less able to ensure our own safety. 

Method 4 - third party error + anticipation failure - possibly better due to speed kills policy

This is where an "innocent" motorist driving in excess of the speed limit is affected by someone else's error. Typically it might be someone pulling out of a junction into the innocent motorist's path. In most cases the innocent motorists' principle failure will have been not anticipating the other road user's error. Yes, travelling at a higher speed might make the accident worse. But habitually travelling at a lower speed does tend to make one less attentive to these sorts of risk. Of course this scenario overlaps with "Method 2" above. 

Method 5 - deliberately - no change due to speed kills policy

Assuming the objective is suicide or murder, we don't suppose speed enforcement will be considered. 

Method 6 - mechanical failure - possibly better due to speed kills policy

If you're going to have a blow out, then lower speeds are better. But having a blow out is rare, and serious loss of control following one is rarer still. Only a percent or two of all accidents involve mechanical failure.

Method 7 - "I wasn't going too fast - I was within the speed limit" - worse due to speed kills policy

We know full well that the road safety message is supposed to be: "drive according to the conditions but always within the speed limit." But it isn't always received properly. We reckon that we now have millions of drivers who believe that their speed is safe as long as they are not exceeding the speed limit. This misunderstood message can easily cause excessive speed accidents.

Section summary

Excessive speed is found to be an accident causation factor in less than 10% of accidents according to most studies of real world accident causation. Within that 10% you can find all the accident types listed above. Speed limits have no magic benefit. You can be killed driving within the speed limit or as safe as houses above it. A large proportion (working estimate: 2/3rds) of excessive speed accidents take place entirely within the speed limit.

So lower speeds and speed kills policy might have a positive influence on some of these sorts of accident. It's interesting to note that those accident types which might be improved also involve a clear and different driving error. Mechanical failure is the exception, but is one of the least frequent accident causation factors.

But the largest share of excessive speed accidents come from carelessness, inattention and hazard perception failures - drivers failing to slow down when necessary. These accidents are likely to be more frequent and more severe if we apply blanket speed enforcement.

How are drivers affected?


Accidents happen when people make mistakes. About 75% of those mistakes are carelessness or inattention. About 5% of those mistakes involve excessive speed. The big bother with too many speed cameras is that they alter the things that drivers pay attention to. Too many drivers now spend far too much time considering speed limit, speed, speed limit compliance and the risk of enforcement. Sometimes - too often - these days they are spending precious milliseconds worrying about numerical speed while an unseen dangerous situation is developing ahead.

Every year on our roads we have something like 30 million near misses. If we distract our drivers we should not be at all surprised that some of them are distracted at exactly the wrong instant and something that would have been a near miss becomes a dangerous accident.


Driver attitude is well known to be related to safety. Drivers with better attitudes leave better safety margins and have fewer accidents. But too much speed enforcement promotes bad attitudes, ranging from the careless: "it's not my fault I was only doing 30!" to the angry: "you can't pass, I'm already doing the speed limit!" and the frustrated: "let me past, you're only doing 40 mph and the limit's 60!" 


The absolute cornerstone of earning the safest roads in the World was individual driver responsibility. Speed enforcement and an over reliance on speed limits shifts responsibility for speed setting away from the driver. Such shifts erode one of the core principles of the safety culture that made us so safe. 


These days I receive frequent emails from drivers describing the experience of driving with 9 points on their licences. They report that they are extremely tense when driving and spend a significant proportion of their time looking at their speedometers. Are these people better placed to avoid an accident? No, of course they are not - they are under pressure and their performance is bound to suffer. But it isn't just the nine pointers. Millions of safe and experienced drivers have a constant low level fear of speed enforcement. It's not good and contributes to distraction from safe driving tasks.

Driver skill

Make no mistake, speed enforcement is the opposite of safe driving skills. It sends the clear message that drivers are not to be trusted to set appropriate speeds. And it denies those who are skilled enough to set high appropriate speeds in good conditions the right to benefit from their skill. The more we emphasize tight controls the less we encouraged safe skilled behaviours. It is wrongly assumed that "we can afford to do without" drivers setting appropriate speed for the conditions. 

Safety Priorities

In those few seconds or few tenths of a second before an accident is it more important that a driver should be giving priority to what's going wrong ahead or to his speedometer? Since every single accident and near miss is preceded by opportunities to avoid, it should be obvious that the greatest safety priority should always be accident avoidance. Reading the speedometer has no place in the drivers' accident avoidance tool kit.

Time to react

This is the single jewel in the rusty crown of speed enforcement policy. If drivers are going more slowly when something goes wrong, then they'll have more time to react and avoid or minimize a collision. But this jewel turns out to be a nasty bit of broken glass. Time to react is not usually delivered out of free travelling speed, but from adjusted speed as a hazard is encountered. We saw more detail in Method 2 - carelessness, inattention or hazard perception failure above.

Driver Concentration

It is very well known amongst skilled and advanced drivers that lower speeds demand lower attention, and that lower speeds promote lower attention. If we slow down vehicles over a wide area, particularly if we slow them significantly below the speeds that drivers are currently choosing, we risk increasing accidents due to inattention, poor concentration and sleepiness. Driver concentration is precious and must be encouraged and promoted.

Driver attention

Tiny changes in average driver attention can make accidents out of near misses. “Speed kills” road safety policy is making quite large changes in the things that drivers pay attention to. We should not be surprised that fear of speed enforcement is causing lower average driver attention, nor that this dilution of attention increases road dangers.


Speed kills road safety policy and speed cameras:

  • distract drivers from the task of safe driving
  • distract the police from former excellent roads policing standards
  • distract local authorities from road safety initiatives based on sound engineering
  • distract us (nationally) from the real causes of road dangers
Is it any wonder that many more folk are dying on the roads than should be?

And what about all those reduced speed limits? Why haven't we seen a deaths reduction from those?

Real road safety is very much more than keeping to a speed limit. We earned the best road safety in the World by having the best road safety culture (click here). Now we're throwing it all away by concentrating our efforts on something that actually undermines road safety culture.

Speed cameras are no more than highly unwelcome weapons of mass distraction.

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Created 16/10/2003. Last update 7/03/2004