Here’s a problem. In 2022, Manchester City Council say they reduced the speed limit on the Mancunian Way to 30mph. But it’s not clear if they have. It’s not even clear if they can.
Fair warning: this posts plumbs the depths of pedantry in the areas of legislation and signage, so if that isn’t your thing look away now. On the other hand, it does also have some jokes about hats.
At the present time, the only thing we can say with any certainty is that the A57(M) Mancunian Way either does or does not have a 30mph speed limit. Like Schrödinger’s Cat, we won’t know until we open the box.
The physicist Erwin Schrödinger first wrote about his famous thought experiment in 1935. It was meant to be a way of thinking about the problems of quantum theory, which state that particles can be in two states at once until they are observed. To illustrate this in a more understandable way, he created a thought experiment in which a cat is placed in a box with a volatile radioactive substance that may or may not kill it. You can only know whether the cat is alive or dead by opening the box. Until then the cat is in a “superposition” of being both alive and dead simultaneously.
Manchester is presently - and unintentionally - embarking on a similar experiment in quantum speed limits. The City Council says their urban motorway now has a 30mph speed limit, something which appears to be impossible to achieve, and the legislation behind it appears to have a fatal omission.
So far their experiment is untested by the courts. Until a judge opens the box and has a look at the cat, we don’t know what the speed limit is.
Wait. This all sounds completely unhinged. Let’s go through it from the start.
The highway in the sky
Manchester’s famous Mancunian Way opened to traffic in March 1967, and was extremely novel. A bypass across the south side of the city centre, it is almost entirely elevated above ground, causing the local paper to name it the Highway in the Sky. It was one of the most famous and recognisable urban roads of the 1960s.
What it wasn’t, in 1967, was a motorway, despite the fact that it was often called one. When it first opened to traffic it was just part of the A57. For reasons that are not entirely clear it only gained its motorway wings in 1971, from which time its speed limit was 50.
It remained so for several decades, until Manchester City Council took a decision that no road in their care should have a limit higher than 30mph. On 3 November 2022 they applied a temporary order changing the limit.
Manchester’s temporary order expired on 13 April 2024, and we can’t find evidence that it has been extended, so at the time of publication the legal status of the 30mph limit is a complete unknown. (A permanent order has been drafted, and is due to take effect in the autumn, but we’ll come back to that.) However, even overlooking that, the whole thing is on shaky foundations.
A look is all it takes
In the UK, speed limits rely upon a simple concept that was first introduced in 1934. The idea is that a competent driver should be able to understand the speed limit by looking at their surroundings. Generally speaking, a limit is considered enforceable if that’s true.
The criteria for a 30 limit, set back in 1934, was that it applied in an area with a system of public lighting - streetlights, in other words. If you look around and the road has streetlights, the limit is 30. If you don’t see streetlights the National Speed Limit applies. The National limit is either 60 or 70 depending on whether the road is single or dual carriageway - another thing you can normally tell at a glance.
Now we also have 20, 40, 50 and 60 limits, which might override the usual ones. For that reason we use “repeater” signs, which are the little miniature speed limit signs posted at regular intervals at the roadside. They are there so that a competent driver can still look around and tell what the limit is. If there’s a little speed limit sign visible, then the limit is what the sign says.
An exception was introduced with the invention of the motorway. Since motorways did not have shops and houses facing them, they would never be subject to an urban 30 limit. A simplification was possible. So, a competent driver looking around and seeing they are on a motorway can just assume a 70mph limit applies, with or without streetlights, unless there are repeater signs to tell them otherwise. Hence long lengths of rural motorway with street lighting have no repeaters: it’s a motorway, so the limit is 70, and no clarification is needed.
From its creation in 1971 to the temporary order made in 2022, the Mancunian Way had a 50 limit, and had “50” repeater signs throughout, so competent drivers could look around them at any time and infer the correct limit.
The problem on the ground
Let’s assume the role of a Competent Driver and see if we can work out the Mancunian Way’s new limit.
- It’s a motorway, and is signposted as one, so the default is 70.
- It has streetlights, which normally imply a 30 limit.
- The streetlight rule does not apply, because this is a motorway. Therefore the default is still 70.
- There are occasional repeater signs for the 30 limit. So that confirms it: 30, right?
Well, it’s not as easy as that. If we remove our Competent Driver Hat for a moment and try on our Amateur Lawyer Hat instead, we will recall that 30 signs have to be correctly designed and located in order to apply, and some of those on the Mancunian Way (especially the temporary ones on A-frames) use an incorrect style of lettering. Others, at certain entrances to the road, only appear some distance beyond the “start of restrictions” signs, which implies that there’s a 70 limit between the start of the motorway and the first 30 sign.
That’s only the start, though, because our Amateur Lawyer Hat also reminds us about TSRGD.
The Traffic Signs Regulations and General Directions (TSRGD) is the rulebook for UK traffic signs. A sign can only be lawfully erected, and enforced in law, if it complies with the rulebook.
In Schedule 10 of TSRGD, which covers speed limit signs, you’ll find diagram 670, a familiar red circle with numbers inside it. Its description is “maximum speed limit in mph”, and it has a number of instructions that set out the rules for its use. One of them says this.
The sign must not be placed as a repeater sign where the road is subject to a maximum speed limit of 30 mph and has a system of carriageway lighting.
In other words, you can’t put “30” repeaters on a road with streetlights, because the streetlights are what reminds drivers of the 30 limit.
On a motorway, of course, streetlights don’t indicate a 30 limit, but it seems that nobody involved in writing TSRGD had thought of that, presumably because nobody ever thought a motorway might actually get a 30 limit. And the rules are the rules.
The (speed) limits of possibility
Here is Manchester’s problem, then: they have attempted to restrict a motorway to 30mph, but there is seemingly no legal way to convey that fact to drivers. The system of street lighting doesn’t do it, but it is illegal to erect repeater signs because the street lights are there. They have created a road on which it is not possible for a competent driver to look around them and infer the speed limit from their surroundings.
That surely has consequences for whether or not the new limit is compliant with the law. If you create a limit, you must signpost it in accordance with the law, or else it is invalid. And (with the caveat that we are not lawyers and this does not constitute legal advice) it appears that there is no way to signpost this limit according to the law.
The obvious question is whether this can really be the first ever time that someone has tried to restrict a motorway to 30mph. If you’d care to try on this Road Enthusiast Hat - you’ll like this one, it has a pom pom - we will discover that there are at least three previous examples.
The most recent is on the Leeds Inner Ring Road, A64(M), where a temporary 30 was applied during bridge replacement works at the Regent Street interchange. This initially had repeater signs throughout, plus street lighting, just like the Mancunian Way - but Leeds removed their repeaters, on expert advice, in the belief that they would make the limit unenforceable.
There’s a section of M1 with a 30 limit too. A link road cutting through the roundabout and joining the northbound M1 at junction 1, Staples Corner, has a short and widely ignored 30 limit. There is no terminal sign where the motorway starts, and just two repeaters shortly afterwards, despite the road having street lights. Since the requirements for terminal signs aren’t met the limit is probably not enforceable anyway.
The third and final example is unexpected. It's the Mancunian Way itself.
The 50 limit that existed until 2022 was imposed by The Motorways Traffic (Speed Limit) Regulations 1974, which created the 70 limit on motorways that we still have today. It attempted to reset the limits on all motorways, so it had a list of all the ones that had limits lower than 70, and specifically stated that the Mancunian Way - all of it - was subject to a 50 limit.
But the Mancunian Way became a motorway in 1971. Before the 1974 order, its limit was set by the Motorways Traffic (A.57 (M) Mancunian Way) (Speed Limit) Regulations 1971. They said something different.
These Regulations prohibit the driving of motor vehicles at a speed exceeding 50 m.p.h. on the Mancunian Way A.57 (M). The slip roads are restricted to a speed limit of 30 m.p.h.
For three years in the seventies, then, the Mancunian Way’s sliproads all had 30 limits - the first ones ever applied to a motorway. And that was probably the only example we’ve yet found that could be legally signposted: as long as there were signs at the start of the 30 limit, the sliproads are all short enough that no repeaters would be needed before they came to an end. It might just have been possible. It may even have been enforceable.
A legal oversight
Manchester City Council have now published the draft orders that will make the 30 limit permanent, so we do at least know that they intend for it to be permanent and that legislation will soon be in place, even if it isn't at the moment.
According to the notice the Council placed in the Manchester Evening News, the new order will do two things. First, it will establish a new 30 limit on the Mancunian Way, and second, it will revoke the Motorways Traffic (A.57 (M) Mancunian Way) (Speed Limit) Regulations 1971.
What it won't do is revoke the 50mph speed limit provision in the later Motorways Traffic (Speed Limit) Regulations 1974, which is more recent and appears to supercede the earlier 1971 order. It also won’t revoke speed limit orders for the two sections of 50-limit motorway that didn’t exist in 1971 and which were added in the 1990s. So even once the orders are published, and even if the signage problem is resolved, it's not actually clear that the existing 50 limit will be fully extinguished or that the 30 will be correctly established in law.
Where does that leave us?
Suppose a motorist is fined for exceeding the 30 limit, and takes the case to court. The courts may decide that the limit is not enforceable because the signage fails to comply with TSRGD. Or they may decide that the limit is invalid because the temporary order has expired, or that the new order is invalid because the 50 orders were never cancelled. Or, they may decide the Council have made reasonable endeavours to communicate the limit to drivers, despite the signage not complying with the letter of the law, and that revoking the 1971 order is sufficient, and thus declare it enforceable in its current form.
The Mancunian Way’s quantum 30mph limit, in other words, may be alive or dead.
We’re just waiting for a judge to open Schrödinger’s box so we can find out.
Comments
There's also another additional legal question here - does the Council even have the legal power to revoke an SI unilaterally even if they tried with the 1974 Regulations? Usually items passed by Parliament can only be revoked by Parliament.
In time-honoured tradition, I suspect the courts would take the following view...
1. Low social class: Fine or waive, based on ability to pay.
2. Working class: Fine
3. Upper Class: Waive, based on threat of legal challenge.
Would one solution be to convert it into a 'special road', but isn't a motorway?
As a physicist, this was a good read, especially the notion "until a judge opens the box to look at the cat". I think a similar conundrum for councils occurs in Birmingham city centre. No Overtaking restriction signs are used to deter road users from trying to get past a tram in a section of street-running, presumably because they're longer than most people expect. But when stationary at a Tram Stop, could that sign be enforced? Technically, not. Yet how else to convey to drivers / bike-ists that they really shouldn't venture on by?
Maybe BCC should apply to the new Home Sec to add a 'special' sign to those I've gathered here: www.TRC11.com/my-news/how-often-are-new-roadsigns-used
Is the A57(M) not under the jurisdiction of National Highways, rather than the local highway authority?
No, it’s not a trunk road, it’s the responsibility of Manchester City Council. Most motorways are trunk roads but there are exceptions.
Maybe time to move with modern technology and require in car digital displays for signs, to be mandated on new cars and provided for a small charge when you renew your car tax otherwise. Realistically bought in bulk these would not be expensive seeing as you can get sat navs for £23 nowadays.
Much as road afficionados think things like street lights = 30mph unless it's a motorway or there are repeaters most drivers don't understand it, even though they should. Put a big lit up 30mph on their dashboard and there's no debate. Could even highlight new limits people are forever moaning about being "caught out" in and save a load of money erecting millions of poles and aluminium plates.
Great idea in theory. Need to make sure the feed is 100% accurate though - my satnav sometimes tells me the wrong speed, and there can be a delay to update when you pass into a new limit area. At best it's a backup for when you missed the sign.
If you live in the UK or EU all new vehicles (from a few weeks back) have a device that does this and attempts to prevent you exceeding the speed limit.
I know that certain local authorities, for example Bath, seem to have lowered the vast majority of local road speed limits by about 10mph over the past decade or so on all but a few roads (eg: 60/70 becomes 50, 50 becomes 40, 40 becomes 30 and 30 becomes 20). Is Manchester somewhere that has taken a similar approach, and if so would this be an example of this? As far as I know there is nothing in motorway legislation that theoretically prevents a 30mph speed limit (and such limits have been in place for certain major roadwork schemes in the past, I think one of them being the major structural works on the elevated stretch of M5 near Birmingham), and I have a feeling the A57(M) is one of the few motorways that is maintained by a local authority rather than National Highways.
I think the 30mph sign on that M1 sliproad was likely placed there in error by a contractor and should have instead been a white rectangular "Max speed 30" sign (since it's on a tight looking bend where these are common), which is only advisory.
Your observation that road speed limits have dropped by around 10mph on many roads around the UK is accurate, and is explained here in To The Limit: The Numbers Game.
In short, a 2006 change in guidance from the Department of Transport means the "default" speed limit for a given road is now a few MPH lower than it was before, which when rounded means 10 MPH lower, and local councils have been encouraged to review their roads' speed limits against this new guidance.
P.S. I highly recommend the whole To The Limit article, it is fascinating to understand how we got where we are. Also shows that, to me, history is repeating itself with respect to the new 20mph Restricted Road default in Wales. Apparently Welsh politicians didn't know that the limit used to be 20mph and it was raised to 30mph precisely because the 20mph limit was widely hated and ignored... Those who don't learn history are doomed to repeat it, I suppose.
Those that widely hate and ignore the 20mph limit are as wrong now as they were then. Councils should have just had the guts to keep it in the first place, rather than pandering to people who are apparently unable to control their two ton boxes at such a speed.
Firstly, the 20mph and 30mph change was done centrally by the government in Westminster - local councils were not involved in any way. Indeed, I don't believe that local councils gained the ability to set local speed limits at all until sometime later - though I may be mistaken in that.
Secondly, I would posit that, if anything, the 20mph blanket limit was more appropriate then than it is now: vehicles were generally less capable, less safe, and driver education was also less than it is now. Yet between 1930 and 1934 not only did they raise the urban limit from 20mph to 30mph, they also abolished the rural limit entirely, and the article I linked actually states accident rates fell in the two years immediately after they did so, suggesting that limits tailored to the situation are more effective than arbitrary blanket limits.
Thirdly, you are entitled to your opinion of course, but the 441,288 Welsh citizens (and 28,283 others) that signed the petition against it appear to disagree with you. My own view is that 20mph limits are appropriate sometimes but the "blanket limit with occasional exceptions" approach taken in Wales was unnecessarily draconian; the ire it drew from the public both reasonable and entirely predictable. Had more care been taken to ensure that main through-fares in towns and villages were kept at appropriate higher limits (as is now being done retroactively), I think the backlash would have been much less.
I believe the following quote from Chris's article is pertinent to this discussion:
British drivers are, of course, taught to "read" the road so that they can judge a safe travel speed. Motorists are assumed to be intelligent and responsible, driving to the conditions and not blindly powering along every road as fast as the law will allow, but it's a double-edged sword. When the speed limit doesn't match the driver's perception and judgement, they will naturally select their own speed — which may be higher than the number on the sign. In a nation where drivers are expected to think for themselves, simply changing the rules and expecting blind obedience won't always work.
Your comment is absolutely the best one on here, well done.
I've sometimes wondered whether in certain situations, breaking the tradition of multiples of 10 mph would help, e.g. a compromise 25 limit on some roads in Wales instead of the new 20 in place now. Is there anything in law which prevents this?
This is governed by Section 84 of the Road Traffic Regulation Act 1984 (as amended). Subsection (1b)(b) gives Westminster and devolved governments the power to prescribe what limits may be set by a speed limit restriction order. I have not yet been able to find any regulations made under that power, however, I suspect one exists and that regulation would therefore govern which speed limits may be set.
I also checked The Traffic Signs Regulations and General Directions 2016 to make sure that doesn't have a restriction on the signage, but it simply states the numerals on the sign may be varied without specifying any particular acceptable numbers.
So, the short answer is its not set in primary legislation, but a restriction probably exists in a secondary legislation regulation somewhere. Said regulations could be changed by suitable ministerial action under the power granted by RTRA section 84.1b.b.
IIRC, UK speedometers are only required to have intervals of 10mph units so any speed limit ending in a 5 is unenforceable as the aforementioned competent driver is not guaranteed to be in a vehicle that could display that level of accuracy
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Sources
- Temporary speed limit order expired: Mancunian Way - Road Traffic Regulation to Reduce the Speed Limit to 30mph, Public Notice Portal, 4 December 2023.
- Original 1971 speed limit order: Motorways Traffic (A.57 (M) Mancunian Way) (Speed Limit) Regulations 1971, described in The London Gazette, 29 June 1971, page 6957.
- Revised 1974 speed limit order: The Motorways Traffic (Speed Limit) Regulations 1974, Legislation.gov.uk.
- Draft permanent 30mph order and provisions: The Motorways Traffic A57(M) - (Mancunian Way) (30Mph Speed Limit) Scheme 2024, Public Notice Portal, 17 July 2024.
Picture credits
- Photoographs of new temporary and permanent 30 signs, and entry point with no speed limit sign, are courtesy of Bryn Buck.
- Photograph of entrance sliproad to M1 is taken from an original by Jaggery and used under this Creative Commons licence.
The M6 Toll has at least two places where it's a motorway with a 30mph speed limit and street lights, as it has been since it opened 20 years ago, but I don't think anybody has questioned it, presumably because the physical barrier means a responsible driver can't speed by much anyway.