The influence of traffic signs goes way beyond transport

During the past few weeks, there have been many news stories about the removal or modification of certain metric traffic signs by an elderly gent from Huntingdon and his friends. Their inability to see beyond the narrow remit they have set themselves has become very clear. In this article, Ronnie Cohen puts forward a contrary view.

The use of miles and other non-metric units on traffic signs has an enormous influence on Britons’ choice of measurement units. The use of non-metric units on official road signs is not just a transport issue. It affects almost every aspect of daily life in the UK.

An oft-repeated government claim is that, “Road traffic signs are inherently local in their scope ….” Really?

This implies that the system of medieval units used on road traffic signs is a self-contained system without any effect outside the road network and that the rest of society can go fully metric while the medieval units on the roads can stand alone. Two measurement systems, side by side, used for different purposes. If this is such a great idea, why has only one country persevered with it for over forty years?

So let’s see where miles are actually used. Beyond their use for speed and distance signs, car specifications and reviews, speedometers and odometers, miles are also used in the following aspects of daily life in the UK:

  • Wind speeds in UK weather reports
  • Television programmes and documentaries, of which the current Planet Earth II  series on BBC1 is a good (or rather bad!) example
  • Non-profit and commercial websites
  • Online maps, commercial atlases, maps featured in articles
  • Distances to places shown on websites
  • Everyday conversations among British citizens
  • Travel distances (e.g. train journeys, plane journeys)
  • Sports races (e.g. horse racing, motorcycle racing, motor racing)
  • General media reports and news
  • Vehicle and projectile speeds
  • Some signposts
  • Transport projects, such as high-speed rail and airport expansion plans
  • Area descriptions and features (e.g. pleasure piers, beaches, distances to city centres, road distances, runway lengths, etc.)
  • Legacy train systems (e.g. plaques/markers with references showing miles, chains and yards, train speed limits)
  • Mileage allowances (e.g. pence per mile)
  • Taxi fares and tariffs
  • Private sector speed limit signs
  • British books, magazines and newspapers of all kinds, especially the non-specialist media
  • Public debates and government communication with the general public
  • Dialogue in films produced in the UK and the USA, the two big users of the mile
  • Police reports about traffic offences
  • Tennis serving speeds

This is a long list but probably not an exhaustive list of the common day-to-day use of miles in the UK.

Transport Ministers and their advisors can not really believe that “road traffic signs are inherently local in their scope”. They must, surely, see the enormous influence of official road signs on the way that Britons think about distance and speed, and its huge impact on the British media and political and media perceptions about Britons’ understanding of metric units.

Transport Ministers have also said that “The significant costs involved for the UK in changing the measurements used on signs, replacing signs, providing safety and publicity material and the consequential costs for businesses and other organisations would far exceed any benefits … and clearly consideration must be given to ensuring that costs are not disproportionate to overall benefits.” The greater costs to the UK economy of having two measurement systems, neither fully understood, have always been ignored.

Paradoxically, the Government accepts metric measures on the incident location and marker system on motorways and major A-roads yet resists the use of metres on emergency exit signs provided for safety reasons in UK tunnels. Presumably each is considered local in scope.

Finally, it should be pointed out that this issue has implications for the UK’s survival as a trading nation with a large and healthy manufacturing industry. To improve its productivity and to survive in a metric world, the UK needs a workforce that is familiar with metric units. And familiarity comes, not from studying textbooks, but from daily use. Which is where road traffic signs could make a significant contribution, if only they were metric.

34 thoughts on “The influence of traffic signs goes way beyond transport”

  1. More important than the articles themselves are the comments in which an overwhelming number of commenters considered the actions of this “elderly gent from Huntingdon” to be vandalism.

    The support for metrication was overwhelming and counters those among the opposition that claim the general population want to retain imperial.


  2. I read this story in my local newspaper in Huntingdon, I still see metric signs around they always look brand new too. Could this be why my council tax is high? But seriously taking down signs is criminal damage and could lead to someone being injured or even killed. Is it worth it just for tradition?


  3. @RonnieC

    Excellent post! And spot on as well.

    However, it was disheartening for me to read how many aspects of UK daily life still include “miles” … it’s even worse than I had imagined (from this side of The Pond).

    I must confess that, even though I am a fervent advocate of converting road signs to metric both for simplicity’s sake and for the “knock on” effect on other areas of daily life, I am truly astonished at how powerful such a presence (of metric road signs) is on a nation’s mental framework. This is evidenced by the continued use of “kilometers” in Canada despite the Conservatives in Ottawa having put the brakes on metrication years ago and the omnipresent “Imperial” drag on Canada due to the overwhelming presence of the USA just south of their border.

    Every time I turn around I hear Canadians using “kilometers” exclusively in place of “miles” (and they have been doing this consistently for years now).

    Interestingly, Canadians did the same thing when they ditched Fahrenheit in favor of Celsius only (so that all the thermometers I’ve seen there use Celsius exclusively, all the CBC weather forecasts also use only Celsius, the other media such as newspapers do likewise, etc.). The result when it comes to Celsius is the same as for kilometers … all Canadians I have talked to think only in Celsius.

    This is true even to the point where one Canadian fellow who works here in my building and has lived down here for years confessed to me that he still has a hard time understanding Fahrenheit. I also think of an American radio show I was listening to where the host was talking to a woman in Nova Scotia; when the host mentioned a temperature in Fahrenheit, the woman simply replied “I’m sorry. I just don’t understand Fahrenheit”.

    While you guys are much closer to Ireland than I am, everything I have seen or heard suggests that the conversion of road signs there to metric has had a similar effect as it did in Canada.

    Let’s home someone eventually ends up running DfT who realizes it is important to ditch Imperial on road signs once and for all.


  4. @ Lee:

    No, of course not, is the answer to the question in your last sentence. Road signs are not about ‘tradition’. They are there to provide clear, concise information to road users, all road users including pedestrians. They must be clear and understandable by everyone who sees them and needs to act on the information given. So even if a sign only applies to a small, local area, it carries information that anyone, wherever they come from, from within the UK or elsewhere, should be able to understand immediately. That information is best conveyed using standard, internationally recognizable signs using metric units and pictograms which do not rely on the use of text in English, Welsh, Gaelic or anything else that may not be immediately understood by the road user. Anything other than that exposes road users to risk.


  5. Another consequence not quite covered in the article is the effect on education.

    There is a big hole in government thinking on educational standards etc. The learning process is not confined to the classroom nor is effective measurement of progress confined to the exam room.

    Mathematics is one subject that suffers most from that disconnect!


  6. I have seen digital thermometers that are switchable between degrees Celsius and degrees Fahrenheit. If the temperture probe shows 50°F and one warms it gently using one’s fingers, the display will go up:

    Notice that the step increment is usually 0.2°F, but sometimes 0.1°F. Notice also that sometimes successive reading all have even numbers as the final digit and sometimes odd numbers. If the thermometer is switched to degrees Celsius and the exercise repeated, the increment will always be 0.1°C. This tells me that the electronics inside the thermometer was designed around one bit being equal to 0.1°C and its range of -50°C to +50°C suggests that a 10 bit ADC was used. (The quoted range needs 1001 distinct values and a 10 bit ADC have 1024 distinct values).


  7. @ Martin Vlietstra says: 2016-12-08 at 17:22

    I guess that is exactly the reason that class III weighing scales used for trade are legal only in the units in which they are calibrated, that is metric in UK. They are not legal for trade when used in ‘converted’ units, I have no idea how they get round this in USA.


  8. #Ezra
    Are Canadian car speedometers now dual or just km/h ?
    Most U.K. car speedometers are dual, primary mph with secondary km/h usually printed very small!


  9. @Rob

    CMVSS 101 requires km/h, allows dual. It parallels but reverses FMVSS 101 in the US which requires MPH but allows dual. The acronyms stand for Canadian and Federal (US) Motor Vehicle Safety Standards, which are a matter of law.

    The domestic auto industry is almost entirely dual, imports mixed. The domestics have advocated that the law should recommend or require dual. If it is an analog speedometer, the inner ring is almost uselessly small. If the law required dual, I think it would need some “equally readable” requirement. Right now, it is an afterthought.


  10. Rob:

    As someone who lived in Canada for over 30 years, perhaps I can answer. From the time Canada converted in September 1977 right through to today, in general the following is the situation:

    North American vehicles (Chevrolet, Ford, Chrysler) have dual metric-predominant speedometers.

    Same goes for Japanese and Korean vehicles (Toyota, Nissan, Honda, Kia, Hyundai).

    European vehicles (MB, Audi, BMW, VW, Volvo – and Saab when it was in business) generally have metric-only speedometers (even the Mexico-assembled Golf I rented earlier this year to Canadian spec). In regards to Saab, I once had a 1978 Saab 99 which I took into the USA when meeting a contractor. he was astonished to see the speedometer go up to 200 – not realising that was km/h. I tried to explain that to him, but km/h might as well have come from the planet Mars for all he understood.

    The above speedometer displays may be modified on digital dashboards – my daughter’s Hyundai Santa Fe has a digital display which can be switched between dual km/h-predominant and dual mph-predominant. Fuel consumption display changes accordingly (between L/100km and miles/US gallon). However, as my daughter has never driven her vehicle into the USA, she has never changed the display.

    In all cases, odometers are only ever in km.

    Hope this helps.


  11. The Canadian Driving website has an article from last year that has a really nice photo of a car dashboard as built and sold in Canada (just scroll down a bit in the article):

    I am very impressed by the km/h-only speedometer and both coolant temperature and ambient (outdoor) temperature only in Celsius plus the fuel economy gauge in l/100km (note the lowercase “l”) and both the regular odometer and the trip odometer in “km” only.

    In fact there is not a single hint of Imperial anywhere on the dashboard. And we’re talking about Canada here (where the drag from US Customary in the nearby USA is huge, unfortunately). That tells me that the only reason there is still a metric muddle in the UK is because the government has failed the people. 😦


  12. @ronniec:

    Of course, we’d soon find out how `inherently local in their scope’ DFT genuinely regard road signs to be if some enterprising highway authority (or AA, CTC et al) took it upon themselves to start installing metric-only versions…

    Note also that BSP threaded plumbing has spread the imperial inch even to the most metric of countries, although the standards are probably now `soft’ conversions.

    @Daniel Jackson:

    There has been approximately one [old] story about sign vandalism, but it has recently been repeated by many outlets and even translated into other languages. One suspects the reason for this is that it paints the UK permanent civil service in a very unfavourable light, contradicting what the world was invited to believe shortly after the EU referendum. From a foreign perspective, it must come across as a government being completely unable to get a grip on sabotage by a few elderly loonies—setting the tone for prospective EU divorce and/ or international trade negotiations.


    It could very well lead to injury or death if they were to try it with any of my signage!

    @Martin Vlietstra:

    Blimey, so they do. Also true of a generic -42 °C to 550 °C IR thermometer—resolution of a consistent 100 m°C (or inconsistent ~0.1/0.2 °F, when temporarily switched to Fahrenheit) apparently across the whole range. It’s conceivable that digital load cells do something similar with Newtons, but this is more difficult to observe on weighing scales which always attempt to estimate mass from the measured force.


  13. The reason metric signs get vandalised and the authorities do nothing is due to the claim that metric signs are illegal. If they are, then the law needs to be changed to allow them. Even if the DfT never plans to metricate road signage en masse it should be perfectly legal for any community authority to legally erect a metric sign.

    If they are not illegal then the DfT needs to openly clarify this to make if known for once and for all that metric signs are perfectly legal and any vandalism will result in an arrest and conviction as well as the vandal being forced to pay for the restoration of the damaged signs.

    Even if inch based pipe threading is found in metric countries it doesn’t automatically imply people encountering it will know inches nor does it require the populations of these countries to have to learn it. Those who do encounter BSP pipe recognize these sizes as simply trade descriptors. In many cases the descriptor doesn’t reflect a measured value. Trades persons in metric countries will purchase pipe in metre lengths and when installing use millimetre tapes or rulers. Inches are never encountered.

    There is a metric pipe thread series that is gaining ground.

    Click to access thddata22-1.pdf

    Even pipe diameters have metric designations or trade descriptors:

    Notice that the metric descriptors are not direct conversions of the inches and are in fact closer to the actual pipe size than the inch names are.

    A divorce from the EU will work in the favour of the EU. The Americans always wanted the British in the EU in order to counter the influence of the French. The British were always a thorn in the side of the EU with its constant derogations and blaming the EU for every ill. I think every EU leader is relieved that with the UK departing the EU will have the power to grow and move forward.


  14. Daniel Jackson is right. The British should have the clear right to use metric measures on signs. The law needs to be clarified.


  15. How is a story from late November ‘old’? We are aware of the almost fetishistic fascination with newness and modernity by many who favour the undemocratic forcing of the onto those who do not wish it, but less than three weeks and this is ‘old’? What is this, Twitter? :laughing:


  16. @Daniel Jackson:

    Could’ve, should’ve, would’ve. As the ARM stories accurately portray, DFT currently does de facto find itself siding against councils putting up metric signs. Ironically, I think they do it mainly to save face rather than through entrenched opposition to metrication. From the outside, this might look like either laziness or going to extraordinary lengths to avoid the work associated with any change. Pretty irrational really, as it wouldn’t be them doing most of the work…

    There is an element of `trade descriptor’ to BSP, but don’t shoot the messenger. It was a Slovakian plumber in the Netherlands who tipped me off about `half inch fittings [being] three fourths across the threads’—and once you start looking, you see it all over the place wherever iron or steel pipes are involved, not merely plumbing. The vast majority of plumbing here is unthreaded and plastic(s) or copper which have been exclusively metric since ~1970. Practically all appliances use metric threads throughout, too. So Mr. Whitworth’s influence is wide but not very deep,* whereas DFT’s influence is deep but not very wide—and their affectation that it is not is untruthful.

    Yes, everyone knows why we are in the EU. In other news, Project Fantasy are still opining that UK–EU divorce and trade negotiations will be conducted in parallel and concluded within two years :-)!

    * :- Although he is also credited with the imperial milliinch; still much beloved by USA machinists, IME.

    @Active Resistance to Metrication:

    `Old’ as in like a [stuck] 250 mm gramophone record, cynically re-released in an updated 2016 sleeve but with all the original hissing and crackling retained intact…


  17. @Michael

    The British DO have the clear right to use metric measures on their own signs on their own premises. What they do not have though is the right to put up official public road signs which do not comply with the, already perfectly clear, prevailing road sign regulations – regulations set and endorsed by the democratically elected and accountable UK government.

    Is it any different in Australia – could an ignorant or rogue government official or road worker there expect to be allowed to erect an official public road sign which did not comply with the Australian road sign regulations and expect the sign to remain intact because it used his own personally favoured colour scheme, language, units of measure, pictogram or whatever?


  18. If a democratically elected local council decides to put up a sign that uses metric measures on a walking track, its decision should be respected It is not for busybodies to go round changing the signs on the pretext that a ginger group says that the sign is illegal The law should be clarified to make it clear that there is a distinction between road signs and other signs.


  19. Charlie P

    Australia is a metric country and all the road signs have been metric since July 1974.


  20. @Michael

    I know Australia is metric, that isn’t what I asked.

    I’ll restate the question:
    An Australian government official or road worker might, for example, have their own personal view, different from that of those empowered to maintain the regulations, as to what the colour scheme, pictogram design, language or evenn units of measure, should be on Australian road signs. Should the Austalian law be changed, do you think, to be flexible enough to accomodate the foibles of such personnel – as you apparently think it should be in the UK?


  21. @Charlie P:

    You are being disingenuous, as ever. Private premises more often have a statutory obligation—with criminal sanctions, unlike highway authorities—to post metric signs. ARM vandalise those, too. DFT is wholly unelected. The politicians attached to it, themselves not elected in a truly democratic manner, are there to provide a theatrical distraction rather than even the thinnest veneer of accountability. The current TSRGD is clear, but not `set’ (and barely `endorsed’) by politicians—and can easily be changed. Any suggestions for resetting a whole roads board gone rogue? I do, but you (and UKMA?) might prefer something less comprehensive…


  22. Hi Charlie,

    The answer to your question is NO. There is no dispute about road signs in Australia. That was settled more than 40 years ago.

    However, the situation is different in the UK. Of course the road signs are marked in yards and miles, with dual signs for height and width restrictions. However, distance signs on walking tracks are something else. I think that if a local council marks a walking track with the distance in metres, this should be no problem. I don’t think it’s right that busybodies should be going round and changing these signs to yards and miles.


  23. @ Michael Glass says: 2017-01-07 at 04:48

    Absolutely correct.
    For my part the road signs (TSRG compliant) are one thing, and the Imperial ruling is clear.
    However, stay away from our metric countryside signs. OS maps have been metric for years now. Many (a good many many) parks, gardens, seaside (tourist) towns, rural walks and footpaths are metric and metric only.
    Keep your grubby hands off of those signs, keep your stupid Imperial road signs if you must, but let those that choose, actually choose and be accepted. Freedom of choice really being allowed to happen.
    Miles, yards, feet, inches (in this context) are for cars on roads and for no other purpose.


  24. Metric signage for non-traffic purposes may or may not have the law on its side, and the minds of those who exploit the uncertainty for political purposes and make hypocritical claims to be defending the law and acting in the interests of democracy.

    Metric signs do at least have common sense on their side.


  25. I posted above that road signs are not about tradition but are about providing clear, concise information that can readily be understood by all road users, wherever in the UK or further afield they come from. One person has disliked my comment. I invite that person to explain what exactly they disagree with in my comment.


  26. Since most cars will tell you the speed of the road you are driving on, and most speed signs are digital that flash the speed limit in mph which can be changed to km/h so there’s no excuse to change over eventually when the time is right.


  27. @Lee kelly
    ” … most speed signs are digital that flash the speed limit in mph which can be changed to km/h … ”

    The fly in the ointment for this one is that digital signs have only two digits. This is fine for rural speeds, but the ammunition is there as all motorway and open roads would need three digit signs, unfortunately an expensive upgrade. It is I am sure an issue that has been know for many years, and I can be equally sure it has never been factored in (even deliberately factored out). Running information signs of course can handle this.
    If anyone has any real knowledge on this I would love to hear it.


  28. @Ezra Steinberg

    This looks like another media ‘non story’. The same could surely be applied to every speed limit sign which, by it’s very nature, has a different speed on each side of it! As you say, it is a pity things like this cause confusion and seem to warrant media articles.
    This does show what an uphill struggle we are going to have when we do eventually change!
    Sorry, I am somewhat confused by the confusion.


  29. Oh! I just noticed and point out for the American and Canadians here, the blue car appears to be driving on the wrong side of the road! No wonder then at the confusion. I stand corrected.


  30. This highly informative BBC article describes all the ingenious ways roadway designers help drivers (and pedestrians and cyclists) do the right thing to be safer drivers, riders, and pedestrians:

    So, if they can do all this, why not something as simple to promote safety and consistency as metric road signs? All they need to do is ask the ministry in Dublin to send over a copy of their cost estimates and conversion plans! 🙂


  31. BBC Two recently broadcast what appears to be an amazing documentary on the extinction of the dinosaurs, which it claims was caused not just by an asteroid striking the Earth 66 million years ago but by the fact that it hit at precisely the worst possible spot on the planet to create a mass extinction. (I say “appears” because I’m not allowed to view this show since I live in the USA. Most unfair, say I! 😉

    Where this intersects with road signs and metric (or Imperial) usage is evident in this article (Dinsaurs were minutes away from surviving extinction, says new research) about the BBC program that appeared May 19 in The Independent:

    While metric is used for depth measurements, temperature, etc. only Imperial (no metric equivalents) is used for speed and larger distances. It is painfully obvious that the persistent presence of “miles” and “miles per hour” on road signs is at the root of this continued use of those units in the UK instead of “kilometers” and “kilometers per hour.

    While as an American it is not my place to take a position on the possible break-up of the UK, I feel fairly certain that unification of Northern Ireland with the Republic and an independent Scotland (which could eventually happen because of Brexit) would very likely see the metrication of road signs quickly occur in both of those places.

    I wonder then how long just England and Wales would hold out before DfT finally saw the light and converted road signs there as well. If they did, the net result would be the rapid disappearance of Imperial both in the street and in the media.

    Then it will be our turn in the USA to finally catch up with you guys!


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