This is an archive document for historical reference only.
In 2006 the government changed the advice given to local authorities on speed limit setting.
See Speed Limit Objections for the current document.
In many parts of the country, local authorities are setting new, lower speed limits. In many cases these are inappropriately low. This is not only in contravention of government guidelines but will be detrimental to long term safety on our roads.

The Association of British Drivers has therefore prepared an Action Pack, in the form of the following document, which tells you exactly how to oppose the setting of inappropriate speed limits in your area.

Please save this page, print it and use it to help preserve sanity and safety on our roads.

1. How speed limits are set

Local highway authorities are able to set speed limits by making an order under the provisions of the Road Traffic Regulation Act 1984. The point is, anyone can make an objection to a proposed speed limit and the highway authority must give proper consideration to any objections received. This means that, if an objector raises issues which were not considered by the authority when it resolved in principle to set the speed limit, then those issues must be put before the elected members of the authority. A decision is then made on whether to proceed with, modify or abandon the proposal.

Highway authorities have to take objections seriously and give a reasoned justification for rejecting them, otherwise they could lay themselves open to challenge in a judicial review. This would obviously be a very expensive course of action and one which few individuals would be able to contemplate, but authorities are unlikely to take the chance, especially if an objection is submitted by someone who seems to know what they are talking about. A number of similar objections making the same points also carry more weight than just one. It is not a good idea, however, to send several copies of the same letter signed by different individuals. Local authorities are suspicious of such orchestrated campaigns. It is much better if each individual composes their own letter.

2. Other Traffic Regulations

The advertisement and objection process applies not just to the setting of speed limits but to the imposition of any form of traffic regulation, such as banned turns, weight limits and waiting restrictions. The skill from the traffic engineer's point of view is to anticipate the likely grounds of objection and to address them in the initial report to the authority's members, seeking their approval in principle. Any objections can then be dealt with fairly easily. Few highway authorities will ever have received a serious objection to a speed limit order, so a carefully worded letter could give them a nasty shock!

3. So what can you do?

So what does this mean for those of us who are trying to preserve some sanity in our traffic laws? First, it means keeping our eyes open to what our local highway authorities are proposing. The official notices pages of local papers may not be the most exciting read, but it is worth spending a few minutes a week scanning them for notifications of proposed traffic regulation orders. If you spot a proposal with which you disagree, you must submit your objection in writing, to the address given in the notice and by the published closing date.

In order to make an effective objection, you will need to know the grounds on which the authority is proposing to make the order. Local papers will often report the proceedings of Council committees in their editorial pages. These may give you advance warning of what is proposed, often weeks or even months before the official notice is published. Take note of any controversial proposals and go along to the local library, where the agendas and minutes of all Council committees are available for inspection. You should be able to take copies of any reports you need. If the official notice was the first you heard of the proposal, phone the relevant Council department and ask which committee made the decision and on what date. That will save you a lot of time at the library.

Whether or not you have seen the committee report which led to the proposal, go along to the Council office cited in the official notice and inspect the documents on deposit there relating to it. These will include, as a minimum, a map and schedule specifying the exact length of road involved and a 'statement of reasons'. The latter is important, as you will see later, so you should make a copy of it, word for word. Also make a note of any other information which may be available: for instance, if there is an existing speed limit, which the new order seeks to reduce, there may be a copy of the current order showing the date when it came into effect. This could also be used in support of an objection.

3.1 Summary of Information Collection Tasks

4. Grounds for Objection

So, on what grounds could you object to a proposed speed limit? The Department of Transport issues criteria for the setting of speed limits, so one objection could be that the criteria have not been followed. A 1992 consultation by the DoT on speed limit criteria includes the following significant statement on the purpose of speed limits:

"While the speed limit may apply some downward pressure on the speed of the fastest drivers, speed limits on their own do not reduce speeds significantly if they are set at a level substantially below that at which drivers would choose to drive in the absence of a limit."

This statement reflects the findings of many studies in the UK and around the world, which show that unrealistically low speed limits, far from reducing speeds, can actually have the reverse effect, as drivers treat them with the contempt they deserve. To back up its statement, the DoT recommends that speed limits should be set in relation to the 85th percentile speed of traffic, i.e. the speed at or below which 85% of traffic travels. If the 85th percentile figure is more than 7 mph or 20% (whichever is the greater) above the proposed speed limit, then a higher limit should be chosen or physical measures introduced to reduce speeds. A highway authority should be able to demonstrate, therefore, that it has measured speeds on the road in question and taken the DoT's criteria into account.

I would also expect a highway authority to have analysed accident records for a period of at least three years. If there is no history of speed-related accidents, then what is the justification for the proposed limit?

In a case reported in 1997, a motorist successfully appealed against a speeding conviction on the variable speed limit section of the M25. The speed limit is normally varied automatically in accordance with traffic flows, but in this instance the Police had overridden the automatic system and imposed a 50 mph limit. The motorist was caught by a speed camera. He won his case on the grounds that the Police did not have the right to impose a limit which was not justified by the conditions pertaining at the time. This case makes an interesting precedent which could be brought to the attention of a highway authority planning to impose an unrealistic limit.

5. How to compose a letter of objection

The attached example letter is based on an actual objection submitted early in 1998 against a proposal to reduce a 40 mph speed limit to 30 mph. Right at the start, make it clear that you are submitting a formal objection and the basic reasons for doing so. You can then go on to elaborate them. At this point it is suggested that you quote the statement of reasons given by the Council for proposing the order, so that you can then show why you think the proposed speed limit will not fulfil the Council's wishes. Although they will vary slightly, the wording of the statement in the example is typical of the reasons given for most speed limit proposals. It is worth repeating here and analysing in detail:

"The Council propose to make the above-named Order to restrict vehicle speeds to speeds appropriate to the environment in the interests of safety of all road users."

The phrase "to restrict vehicle speeds" implies a belief that speeds can be reduced by the simple expedient of lowering the speed limit. As already shown, research proves that this is not the case and the Government's advice on the setting of speed limits acknowledges the fact. The current advice is contained in the DoT publication, Circular Roads 1/93 and the example letter contains relevant extracts from it, which can be quoted to the Council. The letter also makes reference to an annex to an earlier DoT Circular. The contents of that annex are reproduced with this fact sheet and make very interesting reading.

The example letter goes on to question whether the proposed speed limit is appropriate to the environment of the road in question. It quotes Annex A to Circular Roads 1/93, which gives descriptions of the characteristics of types of roads and the speed limits most likely to be suitable for them. The contents of that annex are also reproduced with this fact sheet, so that you can compare the descriptions with those of any roads in your area where new speed limits are proposed.

The example letter then asks for evidence that speed surveys have been carried out and whether they show that 85th percentile speeds support the proposed speed limit, in accordance with the DoT advice. Note the request for exact times, dates and locations of any surveys: to be valid, they should be taken off-peak during a weekday and at a point far enough away from any major junctions, sharp bends, etc., which could produce a result lower than the real free-flow speed. The speeds of at least one hundred vehicles should have been checked. If the existing speed limit has been in force for many years and the character of the road has changed little in that time, then question the need for change.

The phrase "in the interests of safety" implies that there is a safety problem and, furthermore, that it is speed related. You should therefore ask for evidence of this and what measures, other than a reduced speed limit, have been considered. Once again, Circular Roads 1/93 can be quoted.

You then make it quite clear that your objection will not be withdrawn unless the Council can satisfy you about the concerns you have raised. Note the request, at the end of the example letter, for your objection to be acknowledged and information provided about the way in which it will be considered. This will be done in one of two ways: either by a report to the committee, to be considered at a meeting open to the public (your letter will be attached to the report and will thus become a public document) or, if the committee has delegated the necessary powers, by a formal consultation between the chairman and the relevant chief officer. In the latter case, the report will still be available for public scrutiny, but it will not be considered at a full meeting of the committee.

It is advisable to be selective about submitting objections: check the road concerned carefully, note its characteristics in accordance with the descriptions given in Annex A to Circular Roads 1/93, take photographs at relevant points to show the road environment as seen by a driver. Be sure that the proposed speed limit really is excessively low, so that you cannot be accused of objecting just for the sake of it.

As a final point, highway authorities are not acting illegally if they impose speed limits which do not meet the criteria in the Government's advice. In most cases, they will have done so in the absence of any objections, because few people will have been aware of their intentions until the speed limit signs appear, by when it is too late. If you object on the basis that the DoT criteria have not been followed, however, they will be on very weak ground if they cannot demonstrate either that the criteria have been met or they can produce a convincing argument as to why the criteria should not be applied in the case in question. A bland statement such as "it is Council policy" is not adequate and should be challenged.

If you think your objection has been dismissed lightly, make a formal complaint to the Council that it has not properly considered your views. If you are still unsatisfied, you can seek intervention by the Local Government Ombudsman. Note, however, that the Ombudsman can only concern himself with whether a Council has followed correct procedures, not with the Council's decision itself. The Ombudsman is only likely to consider your case, therefore, if the Council failed to make an adequate response to your objection. If it did so, but you disagree with the decision, the Ombudsman is powerless.

5.1 Summary of main points when Objecting

6. Example Letter of Objection to a Speed Limit Order

(Replace grey text with appropriate names/values)

Dear Sir,


I wish to register my objection to the above named Order. My reason for objecting is that the proposed speed limit is unrealistic and unjustified for the road in question. I also intend to show that the proposed limit contravenes the advice given by central Government on the setting of speed limits. I note the Council's statement of reasons for proposing the Order to be as follows:

"The Council propose to make the above-named Order to restrict vehicle speeds to speeds appropriate to the environment in the interests of safety of all road users."

It is a fallacy to believe that reducing a speed limit will automatically result in lower speeds. The Department of Transport Circular Roads 1/93, on the use of local speed limits, contains the following statements and advice:

Paragraph 5 — "Specific speed limits cannot, on their own, be expected to reduce vehicle speed if they are set at a level substantially below that at which drivers would choose to drive in the absence of a limit."

Paragraph 6.4 — "Speed limits should be lowered only when a consequent reduction in vehicle speed can reasonably be expected. A survey of traffic speeds should indicate whether a lower limit will, in the absence of regular enforcement, be likely to result in lower actual speed."

These statements reflect the results of experience and research on the effectiveness of speed limits, gathered over many years in the UK and abroad. It has been found repeatedly that when unrealistic speed limits are raised to sensible levels, not only do speeds not rise but they may actually fall, as may accidents. The previous guidance on the setting of local speed limits, Circular Roads 1/80, contains information on UK experience of the effects of altering speed limits, as Annex E to that Circular. I attach a copy for information. Although the Circular itself has now been superseded, the experience on the effects of speed limits remains valid. There is a real possibility, therefore, that if an existing speed limit is lowered to a level which is unrealistic for the environment of the road in question, speeds and accidents could actually rise.

Annex A to the Circular Roads 1/93 contains descriptions of the types of roads for which different speed limits are appropriate. The character of Main Road, which is partially built up with buildings generally set back from the road, clearly falls into the category applicable to a 40 mph limit (as existing). The Circular states, in paragraph 6.6, that "the most important factor when setting a limit is what the road looks like to the road user." It recommends that Annex A is used to establish the appropriate speed limit, which should "then be tested against the results of speed surveys. If the 85th percentile speed of traffic is found to be more than 7 mph or 20% above the proposed limit, then either a higher limit should be imposed or the environment/road geometry should first be altered to achieve speeds closer to the desired limit".

In the case of a proposed 30 mph limit, therefore, the 85th percentile speed should be no greater than 37 mph. If the Council has evidence to prove that this is the case in Main Road, including dates, times and exact locations of surveys, I would be pleased to see it. I note, however, that the existing 40 mph limit has been in force since 11th July 1982, a period of more than fifteen years. I suspect that speed surveys were undertaken at that time and showed 85th percentile speeds which supported a 40 mph limit as realistic. The character of the road has not changed significantly since the existing limit was imposed and I doubt whether actual speeds will have changed much either.

Circular Roads 1/93 also recommends, in paragraph 6.5, that "a study of types of accidents, their severity, causes and frequency can indicate whether an existing speed limit suits present conditions or whether it needs to be changed." The Circular does not rule out the introduction of a speed limit due to the lack of an accident history, but it continues by stating that "such systematic study [of accidents] may well lead to the conclusion that a particular accident problem might be better met by a local safety scheme, than by a speed limit order which would be unlikely in itself to influence driver behaviour significantly." I would be interested to see what analysis of accidents has been carried out by the Council and how, if at all, options other than the proposed speed limit have been considered.

Unless the Council can provide evidence that it has fully considered and complied with Government advice in deciding upon this proposed Order, I will not be prepared to withdraw my objection to it. Drivers have a right to expect speed limits to be applied on a consistent and rational basis across the country. Furthermore, unrealistically low speed limits will lessen drivers' respect for all limits, to the detriment of road safety generally. There is even a possibility that a limit applied with disregard for Government advice could face a legal challenge from a motorist charged with exceeding the limit. In a case some months ago, a driver successfully appealed against a speed camera conviction on the M25, where a variable speed limit applied. It was ruled that the Police had acted unreasonably in overriding the automatic equipment which sets the limit in relation to traffic flow and had manually set a 50 mph limit when 70 mph would have been appropriate. This could be cited as a precedent in challenging a conviction against an unreasonable, fixed limit.

I can sympathise with those residents of Main Road who may consider that some drivers travel too fast, particularly as the road is used as a through route by some motorists between A and B, to avoid the congested A999. I doubt that those residents who may favour a lower limit are aware, however, of the evidence on the effects of speed limits which I have described above and the fact that the proposed reduction in the limit could actually make matters worse.

I would be grateful if you will acknowledge receipt of this objection and advise me of the means by which it will be formally considered by your Members.

Yours faithfully,



Character of Environment Character of Road Traffic Composition
20mph Speed Limit See Circular Roads 4/90
30mph Speed Limit
Built up with development in depth on both sides of the road. Properties with individual access to the road including schools, factories and recreation grounds.
Partially built up lengths lying between 30 mph limits and not long enough to stand on their own as 40 mph limits.

i) City streets and unimproved main traffic routes, or
ii) Main roads through built up villages
Frequent junctions, inadequate visibility for speeds much above 30mph and pedestrian crossings. Few parking and waiting restrictions.

High proportion of two wheeled vehicles. Large number of pedestrians.
40mph Speed Limit
Built up (as above)

Main traffic routes (e.g. ring and radial routes) with good width and layout. Adequate footways and crossing places where necessary. Parking and waiting restrictions.
i) By-passes and other important traffic routes which have become partially developed, or
ii) Main roads through some villages.

As above.

A noticeable presence of two wheeled vehicles and pedestrians.
50 and 60mph Speed Limit
Lightly built up. Some frontage development.

Rural roads. Development not essential but maybe cafes or filling stations or other features which attract traffic, e.g. parks and sports grounds.

Suburban roads or high standard roads on the outskirts of urban areas.

Roads with restricted visibility or junctions or, where dual, gaps in the central reservation. By-passes which have become subject to some development.

Few pedestrians (or full provision for crossing by means of subways or bridges). Few pedal cyclists (or road provided with cycle tracks).



  1. It is a common but mistaken belief that drivers allow themselves a set margin over the prevailing speed limit, and that if a limit is raised by 10 mph, they will travel 10 mph faster. In fact, an increase in an unrealistic speed limit rarely brings an increase in traffic speeds. ("Unrealistic" is here used to mean "substantially below the 85 percentile speed"). It is much more likely that there will be no change, or even a fall. It seems that drivers relieved of the frustrations of too low a limit rarely abuse the higher one. Indeed it is not unusual for the accident rate to fall when a poorly-observed limit is raised. This may mean that reduced frustration leads to changes in driving behaviour conducive to accident reduction.

  2. The evidence for asserting that speeds and accidents do not increase in proportion to an increase in speed limit comes from studies made before and after unrealistic local limits have been raised. Some of the main evidence is summarised in paragraphs 3-9 below.

  3. In 1960, a Departmental Road Safety Committee reporting on the results of the experimental introduction of 40 mph speed limits in the London area concluded that the raising of the limit had resulted in no appreciable change in speeds, while the accident rate remained substantially the same. The committee considered that the higher limit had achieved its purpose of removing unjustifiably low speed limits, and encouraging a proper standard of enforcement.
  4. A before and after study carried out at 20 locations through Kent, where the limit had been raised from 30 mph to 40 mph, showed a fall in speed, or no change, in 80% of the measurements taken, and a small increase in the others. The total number of accidents fell by almost 20%.

  5. In 1973 the Metropolitan Police produced the results of a study on six sections of trunk road where — in accordance with the Department's criteria — speed limits had been raised from 40 to 50 mph, or from 30 mph to 40 mph. At four locations the 85 percentile went up by less than 2 mph and at two locations it went down. Allowing for a general decrease in accidents, the reduction in the number of accidents at these places was 15%.

  6. When the speed limit in Park Lane, London W1, was increased from 30 mph to 40 mph in 1970, the 85 percentile speed fell from 43.6 mph (measured in 1970) to 39.2 mph (measured in 1974).

  7. In 1974, the Midland Road Safety Unit reported the results of a study of a large number of speed limit changes from 30 mph to 40 mph. Their conclusion that there had been no significant increase in either speeds or accidents was in line with the conclusions from a similar exercise for cases in other parts of the country carried out within the Department.

  8. The Department has recently conducted a survey of the effects of changing the levels of speed limits in various parts of the country. The results indicate that raising speed limits has little effect either on the speeds of vehicles or the rates of accidents.

  9. The following examples of local speed limit changes from 30 mph to 40 mph illustrate this point.

      85th Percentile Speed Accident Rate
    County Road Before After Before After
    Cheshire A41 44 43 1.06 0.6
    Lancashire B5253 43 37 0.78 0.85
    West Yorkshire A58 40/43 47/52 1.45 0.65
    Warwickshire A34 42/42 43/43 0.5 0.65
    Warwickshire B4453 42/44 43/43 3.2 1

    The table above shows that, in the one instance in which speeds rose, the accident rate went down.

  10. With the removal of the energy conservation speed limits in June 1977, the national speed limit went up from 50 to 60 mph on single carriageway roads and from 60 to 70 mph on dual carriageway roads. This afforded an ideal opportunity to judge if traffic responds to national speed limit changes in the same way as it does to local changes. A survey of speeds at 49 points throughout the country made in July 1977, compared with a similar survey in July 1976, showed that for cars and motorcycles with a headway of at least 5 seconds there was no change in the mean speed on single carriageway roads and a 1 mph on single carriageway roads and 2 mph on dual carriageway roads (sic). An analysis of national accident rates in the months following the changes shows no evidence that raising the limits caused any increase in the number of accidents.

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