Turning the Screw

How inconsistent, politically-motivated speed limit cuts are compromising safety on our roads

As the enthusiasm for cutting speed limits spreads across the country, 40 mph limits start sprouting on rural main roads.


When I learned to drive in the late 1970s, speed limits were very clear and simple. The limit was 30 mph in built-up areas, 40 mph on many wide, well-aligned suburban main roads, and in rural areas 60 mph on single carriageway roads and 70 mph on dual carriageway roads and motorways. Very rarely you might find a 50 mph limit on roads such as the Mancunian Way. These limits were well understood, non-controversial, and applied consistently across local authorities, with the exception perhaps of slightly different interpretations of where to use 40 mph limits. In general, speed limits were clearly in line with the characteristics of the roads and, so long as you didn't let your speed drift up too far in 30 mph zones, did not unduly concern the average driver.

There had been a couple of changes in the previous ten years or so. In December 1965 a national 70 mph limit was imposed on all non-urban roads, including motorways, which may have upset the owners of performance cars but at the time had little effect on the drivers of family saloons, few of which could then do much more than 80 anyway. Then during the 1973 oil crisis a temporary blanket 50 mph limit was imposed on all roads, which was removed in a couple of stages, but left us with the national speed limit for single-carriageway roads at 60 mph rather than 70 mph as it was before. But there was little evidence that the police were seeking to prosecute people for driving between 60 and 70 mph on single carriageway rural roads, and certainly no Gatsos to enforce the lower limit.

From today's perspective it is startling to realise that until 1965 all non-urban roads in the UK were completely derestricted. And, in the 1960s and early 1970s local authorities were busy increasing speed limits, assessing the speeds on their suburban main roads and replacing 30 limits with 40s, as they had been allowed to do since the late 1950s. In most cases this resulted in only a slight rise in actual speeds, or even a fall. Since the oil crisis of the mid-1970s there have been very few speed limit increases, the only ones I know of being where the road was remodelled and had its character changed.

The 1980s also saw only occasional cuts in speed limits, as local authorities had to secure the approval of the Department of Transport and show that they had conformed to the official guidelines on speed limit setting. However, in the early 1990s this was changed, so councils had complete freedom to set their own speed limits, and only needed to show that they had adhered to the correct procedure in advertising the limit. In theory this was a measure of deregulation, eliminating unnecessary bureaucracy, but in practice it has opened the floodgates for authorities to cut limits all over the place, in a piecemeal and highly inconsistent manner which in my view is now seriously compromising road safety.

Many new roads are now being opened with inappropriately low limits to start with - for example the well-aligned A4/A46 Batheaston bypass in Somerset, a dual carriageway with a grade-separated junction was opened with a 50 limit, and several speed cameras, and you drive on to it from an inferior single carriageway road with a 60 limit. Locally, the A6010 Alan Turing Way in East Manchester, a well-aligned dual carriageway with very little frontage development, passing the new Commonwealth Games stadium, has a 30 limit all the way when it clearly should be 40. Fortunately there are no cameras so far, though! (as of July 2001)

It was also a depressing sign of the times that the limit on the northernmost section of the brand-new A34 Handforth/Wilmslow bypass was cut from NSL (70) to 50 within two years of the road opening, although it must be said that this was a badly designed road in the first place. See here for more details.

Types of Limit Reductions

Being only too well aware of the trend in cutting speed limits, for the last few years I have maintained a listing of limit reductions that have taken place in and around my local area, which can be found here. It is worth saying that the local authorities in my area, particularly Cheshire County Council, have not been as aggressive in cutting limits as some in other parts of the country, and the worst examples I have seen are the responsibility of the Highways Agency.

These reductions fall under a number of basic categories. For each one I have tried to give an example fairly local to me in the Cheshire/Greater Manchester area.

  1. Suburban/village 40s to 30s, e.g. A538 between Halebarns and M56 Junction 6
  2. Extending 30 limits at edge of towns/villages, e.g. through High Lane and Disley on A6 between Stockport and Buxton
  3. Joining up 30s between built-up areas, e.g. A626 between Stockport and Marple. This can be confusing as the road might run through a rural setting, but if there are street lights the limit remains 30 in the absence of any repeater signs
  4. Reduced limits for scattered hamlets, e.g. 40 at Sproston on A54 between Middlewich and M6 Junction 18. Some counties such as Suffolk and Oxfordshire have adopted a policy of implementing a 30 limit wherever there is a settlement of more than 20 houses
  5. 40s in tourist areas - for example covering large areas of Dartmoor and the New Forest. It is very possible these might be employed in the Peak District and Lake District. In the absence of roadside repeater signs, the enforceability of these limits is very questionable
  6. Sub-NSL limits along lengthy stretches of rural main road, e.g. 50 on single-carriageway A624 between Chapel-en-le-Frith and Glossop, 60 on dual-carriageway A34 between Newcastle-under-Lyme and Stafford
  7. Sub-NSL limits on semi-urban grade-separated dual carriageways, e.g. 60 on Runcorn Expressway system, 50 on St Peter's Way (A666) on the sourthern approach to Bolton.
  8. Urban 30s to 20s. This raises a somewhat different issue about the protection of pedestrians which is dealt with in a separate piece Is Twenty Plenty?

As I live in an urban area I am especially concerned at the reduction of 40 limits to 30s on suburban main roads. Typically these are well-aligned roads with good sightlines and few pedestrians, and 40 is a perfectly safe and reasonable speed. By cutting the limit to 30 the distinction between these roads and those through shopping centres, or residential streets, is lost, and it may paradoxically result in higher speeds in the areas where the 30 limit really is needed. In the absence of high-profile enforcement, traffic often continues to travel at around 40 mph anyway. There are still some examples of the correct application of 40 limits in urban areas, such as along the A34 Kingsway in Manchester, but many, such as the A560 through Baguley in South Manchester, and long stretches of the A664 Rochdale Road, have been reduced to 30.

Local authorities are particularly keen on this kind of speed limit reduction as it allows them to dispense with speed limit repeater signs, which are required for 40 limits, but not for 30s. I pity the poor traffic engineer nowadays who has the temerity to stand up in a council meeting and say "this road really should have a 40 limit".

Local residents may be further motivated to campaign to reduce limits from 40 to 30 because they can park their cars on the road without lights in a 30 limit, but not in a 40. I have actually seen this listed as a benefit in a newspaper article about a limit cut.

So Why Not "Kill Your Speed"?

But isn't all this basically a good thing? Won't it reduce accidents if drivers travel a little more slowly?

In reality, it is not as simple as that. The basic principle of safe driving is that you must be able to stop comfortably within the distance you can see, taking into account any hazards you are likely to encounter. This means, that for any given stretch of road, you can determine an appropriate safe speed based on the characteristics of the road and the number and nature of the hazards that may be encountered along it. That then, broadly speaking, gives a speed limit that can be applied.

Research has shown that, while the most dangerous drivers on a stretch of road are the fastest 10%, the next most dangerous group are the slowest 10%, with the accident risk then steadily reducing as you move up the speed graph, with the safest drivers being those in the 80-90% speed range. These are drivers who are not reckless but are able to handle their vehicles in a confident, purposeful way and are fully aware of what is going on around them. This is why experience has shown that speed limits should be set at or around the 85th percentile speed of all drivers on a road. If you slow down already safe drivers, they will not become any safer, and indeed may become less safe if they are frustrated or distracted.

Provided that drivers are travelling at an appropriate speed for the road, there is no safety benefit to be gained from slowing them down further. There is plenty of evidence to show that unrealistically low speed limits actually increase accidents. When in the USA the national 55 mph speed limit on interstate highways was removed, leading individual states to impose limits typically of 65 mph or 75 mph, the accident rate fell. Similar results were often found in the UK in the 1960s and early 1970s when suburban 30 limits were increased to 40 mph.

Problems associated with speed limit reductions include:

  • They have been applied in a piecemeal and inconsistent manner in response to specific concerns, with the result that roads of similar character may have limits that vary by 30 or even 40 mph.
  • This in turn sends out a hopelessly confusing message to drivers. What are you meant to think when driving along a well-aligned trunk road such as the A523 south of Leek, which has a 50 limit, with a derestriction sign at the entrance to the smallest and twistiest country lane leading off it?
  • They are often inappropriate to road conditions and not based on proper road safety criteria. The Department of Transport set out comprehensive guidelines for speed limit setting in Circular Roads 1/93 which are routinely ignored by local councils.
  • They devalue speed limits which are appropriate. In the past, if you came across a 30 limit, you could confidently expect it would correspond with a densely built-up area. Now, you're not so sure, and if you're in doubt about it you may continue to ignore it where it is needed.
  • Limit reductions are often motivated by political factors, not road safety criteria. Councillors feel that if they lower the limit along a stretch of road, they are seen to have "done something" about a perceived safety problem, even though in practice it may result in no change at all in actual speeds.
  • Many limit reductions have been pushed through despite the opposition of the local police force and the council's own professional road safety officers. In these circumstances it is likely they will not be enforced and this will bring the whole system of speed limits into further disrepute.

One of the best examples of how bad limits devalue good ones stems from the growing practice of extending 30 mph limits, fully justified in village centres, well out into the countryside to cover isolated properties. I have been told of an example from the Chilterns where a village had an entirely appropriate 30 mph limit along the main street, which is a "B" road. The council planners then decided to extend the 30 limit out for half a mile into a more rural environment with only scattered development. The result was that drivers came upon a 30 limit in open country, dismissed it as daft, continued at a higher speed which they were then more likely to maintain through the village centre. The council then had to erect "Slow Down" signs where the previous speed limit boundary had been.

There is a similar situation in an urban setting on the A5103 Princess Parkway on the southern approach to Manchester. This is the continuation of the M56, where the limit comes down from 70 to 50 at the end of the motorway, and then again to 40. However, for half a mile after the start of the 40 limit, the road is still a dual carriageway with crash barriers, graded junctions and no adjoining buildings or pedestrians. Not surprisingly, this inappropriately low limit is routinely ignored, the typical speed through the section being more like 60. But then the road goes into an environment where the 40 limit is justified, with adjoining houses, footpaths and a pedestrian crossing. But there is nothing more (apart from a 40 repeater sign) to tell drivers to slow down here, with the result that many drive through this section far too fast (and are then caught by a Gatso hidden behind a sign). Surely road safety would be improved by moving the limit boundary to the start of the built-up zone, and erect a prominent "40" gateway with a warning to beware of speed cameras.

Are Any Reductions Justified?

This is not to say I don't believe any speed limit should ever be reduced. Clearly if there is new development along a road, then the limit needs to be reviewed. But even here the authorities too readily go for a 30 limit when a 40 or even a 50 would have been more appropriate. For example, on the A56 in Cheshire at Preston Brook, between Frodsham and Warrington, there is a cluster of new office development along what was previously a rural NSL road. There are no houses, and the road is not continuously built up on either side, so a 40 limit would have been entirely adequate, but the local authority have chosen to make it 30. Needless to say, the typical speed of traffic is about 45.

It is also generally accepted that smaller communities along main roads deserve more recognition than was felt to be the case thirty or forty years ago. Often this is taken too far, with some councils imposing 30 limits in what are no more than scattered hamlets, but there are locations where it is justified:

  • Furness Vale, on the A6 between Stockport and Buxton, which is in the centre of a stretch built up on one side, where there has (correctly) been a 40 limit for many years. However, there is a clearly-defined village centre, with a pub, a couple of shops, a road junction and houses continuously on both sides of the road, where a 30 limit, confined to the length of road built up on both sides, was introduced during otherwise questionable "safety improvements" in 2000.
  • Sandon, on the A51 in Staffordshire, a fast NSL road which enters a dual carriageway section just south of the village. The road is wide and never continuously built-up, but there is a noticeable cluster of development, with a pub, shop and post office, and I cannot argue with the 40 limit introduced at some time around 1990 - although at a later date it was extended too far to the south along an undeveloped stretch of dual carriageway.

However, for every sensible speed limit reduction there must be ten that are ill-considered and inappropriate.

So What Can be Done?

You can, of course, object to proposals to reduce speed limits - but you have to find out about them first. They have to be advertised in local newspapers, and in notices along the route. But if you don't live in the area and only drive through occasionally you may well not spot a few small notices stuck to lamp posts. Even if you do object, local authorities no longer have any statutory requirement to take government guidelines into account, and this cannot be used as a reason to overturn proposals. The only basis on which the Local Government Ombudsman can overrule decisions is that the correct legal procedure has not been followed to the letter.

This small notice fixed to a speed limit repeater sign may just be advertising a proposed speed limit cut. But how many people would bother to stop and find out?

In practice, it is highly unlikely you will be able to change their mind. I have read the minutes of council sub-committees in various areas where limit cuts have been forced through despite the opposition of the police, experienced highway engineers and IAM observers, and in the face of obvious doubts expressed by the council's own professional officers.

There is some evidence that the central government are aware of the problem of inconsistent speed limits, and it was referred to in their Road Safety Strategy document published last year. Various bodies such as the IAM have urged an overall review of speed limits to ensure they are set on a more consistent basis - and indeed this was specifically proposed in the Conservative manifesto at the 2001 General Election.

By all means raise an objection to proposed local changes, and never fail to point out that they do not conform to official guidelines, but don't imagine it's likely to make much difference.

So probably your efforts would be better used in trying to change the climate of public opinion that cutting speed limits willy-nilly is not necessarily a good idea, and the best contribution to road safety would be made by consistent speed limits, appropriate to road characteristics and based on proven criteria. If enough individuals and representative bodies keep up the pressure on this, there is a definite possibility that central government may restore some measure of control over local speed limits to ensure a more consistent approach, although whether that would lead to many limit cuts being restored is doubtful.

Further Information

You may also be interested in an excellent article by Ben Lovejoy entitled Why Councils Can't Be Trusted to Set Speed Limits which makes many of the same points, although I don't entirely agree with him on the issue of national limits.

There is also a very useful piece from the Association of British Drivers entitled Speed Limits - How They are Set and Your Right to Object which includes details of the widely-ignored criteria for speed limit setting laid out in DoT Circular Roads 1/93.

For information, there is a page on this site briefly setting out the legal position on speed limit signs and markings.

(last updated April 2004)

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