Below is a letter from the CEO of Suffolk County Council to ABD member Alan Dale concerning the blanket speed limits imposed by the county council. This is followed by a response from the ABD, and an analysis of why the anti-speed policies being pursued by the council are wrong.

25th November 1999

Dear Mr Dale

Thank you for your latest letter in which you made reference, albeit separately, to the Association of British Drivers (ABD) and to Suffolkís ìunscientific blanket speed limits.î

The juxtaposition is interesting. In the case of the ABD their website specifically refers to Suffolkís 30mph village speed initiative and presents, as if facts, arguments about the initiative which are confused and misleading but ignore the long established facts about the significant speed reductions which have resulted from the initiative.

With regard to your own comments, you imply that a ìscientificî approach to speed limits would result in a different approach to that taken in Suffolk. I believe that the Suffolk approach was thoroughly systematic and consistent in that it sought the views of local people as to what their speed limits should be, rather than basing restrictions on the behaviour of those people who simply drive through the village. This has promoted local ownership of speed limits, reduced speed and improved the sense of well being for pedestrians, cyclists and local people alike; it has also reduced injury accidents on these roads by 20%. So far, no externally imposed approach has achieved anything like this type of successful outcome elsewhere.

I do recognise that this may be an issue on which we shall simply have to differ.

Yours sincerely

Lin Homer
Chief Executive
Suffolk County Council

A response from the ABD
28 February 2000

Lin Homer
Chief Executive
Suffolk County Council
St. Helen Court
County Hall

Dear Ms Homer


I have been sent a copy of a letter from you dated 25 November to Mr Alan H Dale which is causing me concern. In this letter (copy attached), you refer to the ABD as presenting ìconfused and misleadingî arguments about your speed limit reduction scheme. Indeed, you go as far as to say there is a ìjuxtapositionî when Mr Dale talks about scientific reasoning and the ABD in his letter.

I would ask you either to justify these allegations in full or desist from making them forthwith.

If there is a juxtaposition, it is to be found in your letter, where you imply that your approach is systematic and consistent but at the same time claim that each local community is responsible for its own speed limit.

These cannot both be true — if something is planned and implemented according to a predetermined theoretical framework then it is systematic. If each local community can do as it pleases, then it is not science at all but democracy or anarchy depending on ones viewpoint!

I have to say that I have amassed a considerable file concerning the Suffolk scheme, and I am firmly convinced that it serves neither science nor democracy.

Whilst your criteria for implementing the limits might be consistent, they cannot be regarded as scientific because they violate the DETR limit setting guidelines, which have been shown scientifically to be optimal for road safety.

I am surprised that you say that your claimed 20% reduction in accidents on these roads is higher than that achieved elsewhere. Every safety scheme is accompanied by claims of reduced casualties, and these claims are usually vastly higher than this — numbers up to 75% for reductions in casualties or accidents are banded about. Unfortunately, the overall number of injury accidents on a county basis usually stays the same or gets worse, as it has nationwide during the mid 1990s when all these speed reduction schemes were being introduced, and most certainly has in Suffolk.

Having studied Statistics and Operational Research as part of my degree course I am well aware of the kind of statistical chicanery that can be employed to demonstrate the ìsuccessî of virtually anything, especially when the data is not in the public domain, and I therefore remain cynical in the extreme about your claim of a 20% reduction in accidents.

However, it is your claim to be acting democratically at the behest of local communities which I find the most disturbing. Surely you cannot be suggesting that 450 unsolicited groups of local people approached you simultaneously to demand 30mph limits in their immediate vicinity? No, it is clear that this scheme was initiated and pushed through by Suffolk County Council itself as a matter of policy, with the active support of only a very small number of local residents.

I have seen and experienced the ìconsultationî process for speed limit reductions in many areas of the country. A small print notice is put in the local paper, tiny notices are put by the roadside which cannot be even seen, let alone read by passing motorists. The majority of local people are totally unaware of the impending speed limit until the signs go up, by which time it is too late to do anything about it.

And this majority own cars and choose to drive down the road at a certain speed, which is perfectly safe, courteously slowing when they encounted pedestrians or horseriders. It requires a certain twisted logic to suggest that criminalising the safe behaviour of the majority of the population is an act of service to the community, a logic underpinned by disinformation about road safety on the part of both local and national government.

Unfortunately, even your assertion that you are seeking to penalise those who drive through the village rather than live there does not hold any water. It has long been reported by the police that most of those they catch in speed traps are local residents, often the self same residents who have demanded the trap in the first place. Suffolk is no exception, with one of the Councillors who pushed through your scheme being caught out in exactly this way — apparently you enjoy telling this story at dinner parties!

Since you have built a road safety policy around village parochialism and the hypocrisy of individual drivers, it is not surprising that road deaths are failing to improve in Suffolk. If you are prepared to listen, I have enclosed an analysis as to why the approach that many local authorities have been encouraged to adopt is both wrong and counterproductive. I do hope you will read and digest it.

Yours sincerely

Nigel Humphries M A (Cantab.) Nat Sci., Stats. & O.R.
ABD National Committee

Analysis of speed limit policy
Dear County Council

I would like to take the opportunity to explain to you why I believe your current policy of lowering speed limits and moving towards ever more rigid enforcement is wrong.


These lower limits and accompanying enforcement cause greatly increased stress whilst driving and make many people very angry, but I can understand the pressures that have taken you down this route.

The Government has spent a great deal of money promoting its ìspeed killsî campaign, encouraging local councils to do the same. This has created pressure from local people who have accepted this received wisdom and are pushing for speed reductions which are often either completely unnecessary or not the best way to tackle a specific safety problem. Meanwhile, a political climate has been created by the environmentalists whereby car use is seen as bad and ìbashing the motoristî is acceptable. Some green groups even advocate lowering speed limits simply to make car use unpleasant and so, they presume, to promote other modes of transport.

The vast majority of the population don't agree with this approach — they vote with their feet and exceed speed limits which they perceive as unreasonable. However, very few will speak out against speed reduction measures because they know they will be portrayed as being against safety, and in any case they lack the necessary knowledge to put up a convincing argument. Many even support limit reductions with which they have no intention of complying, and are then surprised when they get caught out — hypocrisy beyond belief.

In this kind of climate, it must be very difficult for any council official or elected representative to resist calls for speed reduction measures, even if they want to.

However, this approach to road safety is deeply flawed and ultimately counter productive, as the road casualty figures, which have shown great reluctance to improve since ìKill Your Speedî began, demonstrate with great clarity.

To understand why, it is necessary to consider the basics of safe driving behaviour, then to look at how speed limits and enforcement affect these when they are used in different ways.


Basic driving skills involve looking ahead, recognising and assessing the road conditions and potential hazards and adjusting speed to take account of what is seen.

The difference between a safe driver and a dangerous one is how well they perform these tasks — this is why new drivers are much more likely to have an accident than experienced ones, despite often driving more slowly overall. It is also why driver training works at cutting accidents, especially when targeted at those with bad accident records, and it is the root cause of why blanket lower speed limits and rigid enforcement can never be effective at improving overall road safety, even if they appear to be so when localised statistics are collected.

This position is consistent with what the DETR say about accident causation. Even in ìKill Your Speedî, speed is only claimed to be a ìcontributory factorî in a third of accidents. Other research by the TRL involving detailed police accident scene questionnaires has established that excess speed is the primary cause in less than 5% of accidents. The biggest causes of accidents all relate to failings in the observation and hazard perception skills that are fundamental to safe driving, and even where speed is a factor, it is usually so because of a failure in hazard perception that has led a driver to be travelling too fast for the prevailing road conditions.

Trying to tackle bad driving using speed reduction alone is therefore rather like treating a broken leg with aspirin — it suppresses the symptoms but allows the damaging medical condition to continue unchecked.


If drivers are to be made safer, then they must be helped in every way possible to both identify and respond correctly to differing road conditions. Road layout, signage, training and public education are all very important ways of doing this, but a speed limit is one of the most powerful tools in the armoury of the road safety engineer because it conveys in one simple number both a warning and a response message. However, to be effective, the speed limit must be deployed in an appropriate and sensible manner rather than as a political tool.

Limits are especially effective when combined with a hazard sign such as a bend, so much so it rarely requires the force of law to make them work in such circumstances. In the more conventional scenario, a speed limit change is a vital way of signalling to drivers that the road conditions are changing and that there may be hazards which are not immediately apparent.

However, to be effective the limit must work with the driverís own judgement rather than contradict his own view of the road when this is soundly based on knowledge of what is actually there. Limits perceived as ridiculous will be ignored and will discredit all other limits, reducing the effectiveness of this important road safety tool.

Blanket limits over a wide area destroy the most effective use of limits — as an indicator of where the road conditions change. Such limits have been known to increase speeds in the most hazardous locations.

Limits cannot be used as a substitute for a driverís own judgement as to what is a safe speed. They are supposed to be set at the maximum speed that is safe and the driver should use his own judgement to set the speed that is safe for the conditions within this.

Unfortunately, many limits seem to be set in an attempt to reflect the minimum speed it is ever necessary to go rather than the maximum. When these are ignored, ever larger and more garish signs are introduced to try to browbeat drivers into complying with limits with which they do not agree there is a need for.

The effect of this is fourfold:

  • It reduces the impact of necessary hazard warning signs which are lost or discredited in a forest of fatuous and pointless road furniture.
  • It prevents drivers from scanning properly for necessary hazards by distracting them
  • It promotes frustration and anger
  • It encourages drivers to see speed limits as a target rather than a maximum — simply obey the limit and you are doing all that is necessary for road safety
There is no need for this — there are many places where the legal maximum speed is far in excess of what is possible without a certainty of collision. In many such places there is no history of accidents, and introducing a lower limit accompanied by signage can only do harm to a situation whereby it is safe to do 40 or 60 when the road is empty but where traffic needs to slow to 5mph to pass a horse should one be present.

The end result is that speed limits as an indicator of maximum safe speed are now totally discredited in many areas, to the point where they are seriously impinging on the ability of drivers to judge for themselves what is a safe speed — after all it is the speed done in relation to the road conditions which matters, not the speed limit.

All of this is predicted in government research from the 1980s which forms the basis of the DETR limit setting guidelines, recently reduced to advisory status in favour of local authority control, and ridden over roughshod by both the Highways Agency and many County Councils and Metropolitan Boroughs.

Speed limits are a good servant of road safety but a lousy master, and need to be put back in their place.

The introduction and availability of automated mass enforcement of speed limits has undoubtedly allowed limits to be reduced below what would be possible without this technology, which has effectively given the authorities the power to impose laws which are not supported by the majority of the population and would not be enforceable by normal methods nor supported by the police.


To understand the role of enforcement of speed limits in road safety, it is first necessary to return to the setting of the limits in the first place and their supposed role in defining the maximum safe speed.

The maximum safe speed to travel varies not only with time, exact location, weather conditions and a host of random factors, but also with the ability and experience of the driver and the car he is driving. Surely nobody would suggest that a grade one police driver in a brand new high performance car cannot safely drive faster than a 17 year old novice in a clapped out Escort. (On second thoughts, if you look at the police training budget cuts but ignore the consequent worsening police accident record, perhaps they can!)

Setting a limit so high that it is never safe for the highly skilled police driver to exceed it under any circumstances would be entirely useless as a method of moderating the behaviour of the novice, who is, after all, the one who needs the assistance to his driving provided by a limit the most.

Even a properly set limit cannot possibly account for all road condition variations, and is at best a compromise. It must therefore be accepted that it is safe under certain circumstances to exceed some speed limits, even if they are properly set, just as it can sometimes be highly dangerous to drive at the limit.

A driver who has his full attention on the road and who is varying his speed according to the prevailing conditions, taking full account of all signage and of the prevailing limit cannot guarantee not to exceed that limit. If forced to do so, his ability to set a correct speed within the limit must suffer, as will his levels of attention directed at hazard perception.

Sensible speed enforcement targets the small minority of drivers who drive without any concern for the welfare of others (or themselves), who a trained police officer can easily spot, and on those exceeding the speed limit where it is dangerous to do so or by a dangerous margin. This will penalise dangerous behaviour and encourage better and safer driving.

Current policy on enforcement tends to specifically target roads where the limit is far too low and where the vast majority of drivers would safely break the limit in normal flow conditions. It is done purely for its own sake and has no safety benefit. Most cameras are set either on dual carriageways or in specific locations where the road topography will lead a good driver to speed up after a hazard and so be caught out.

This is the very antithesis of a good enforcement policy, and is undermining driving standards at a prodigious rate. Not only is proper observation and hazard response made very difficult if not impossible in these areas of high enforcement of badly set limits, but the very act of driving safely is penalised more persistently than dangerous driving.

The policy on enforcement must radically change if road safety is even to stay at the current level, let alone improve.


You must begin to question the wisdom of your current approach, and reconsider what is a sensible and productive way to tackle road safety. I would suggest that you need to start working with people to improve their skills instead of working against them — treating them as if they are all reckless, incompetent idiots.

I appreciate that you cannot change things overnight, but I would strongly urge you to begin moving in the opposite direction to the past five years.

Yours sincerely

Nigel Humphries
MA Cantab. Nat. Sci. Stats & OR

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