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Motorway speed limits cut to 60 mph in bid to reduce carbon emissions

November 26, 2020

By Paul Homewood


h/t Dennis Ambler


Highways England has kicked off a 12-month trial on sections of motorway in England.

In 2019, the transport sector accounted for 34% of the UK’s total carbon emissions, according to GOV.UK. It’s also the UK’s largest producer of emissions.

The UK has set itself an ambitious target to become a zero-carbon country by 2050.

But we won’t reach that target unless the government takes greater action. That’s according to Energy Institute’s Energy Barometer report.

To that end, Highways England has cut the speed limit on certain sections of motorway to 60 mph.

This is part of a trial that it hopes will help bring road emissions down to legal levels.

But one in four (26%) people think it’s not worth the inconvenience*.

How does speed impact carbon emissions?

Speeding up requires power, which burns more fuel. Slowing down uses the brakes, which give off harmful brake-dust particles.

With constant speeding up and slowing down on the motorway, you can see how pollution can build up fast.

Cutting the speed limit to 60 mph rather than 70 mph means less acceleration. This means less fuel consumption, and fewer emissions.

Highways England estimates that a 60 mph speed limit on the motorway could cut emissions by as much as 17%.


No doubt this bonkers idea was dreamt up by some wet behind the ears “expert”, who has no real experience of driving.

What happens whenever you hit a 60 mph zone on the motorway? Cars start to concertina together, which inevitably means more stopping and starting.

You don’t need to be a genius to understand that this increases fuel consumption, not to matter dust from brakes.

Question – where are the AA and RAC, who should be sticking up for drivers’ rights?

  1. CheshireRed permalink
    November 26, 2020 7:32 pm

    ‘Carbon’ emissions.
    We have THE stupidest people who have ever led this country in charge. Ever.

    • November 26, 2020 9:01 pm

      aided and abetted by the wokerati….a more brainwashed bunch of control freaks there never was!

    • November 27, 2020 9:34 am

      Reducing speed lengthens journey times, meaning more vehicles on the road at any one time. And 60mph is the current limit for heavy lorries, so a lot of them will be hard to overtake legally.

  2. Joe Public permalink
    November 26, 2020 7:34 pm

    Of course, the Insurance industry has no vested interest.

    Can we look forward to a premium refund / reduction as and when the change is implemented?

    • November 26, 2020 9:02 pm


    • November 27, 2020 8:45 am


      going slower doesn’t mean fewer accidents, probably the reverse.
      It wasn’t so long ago that there was talk of the perfectly sensible proposal to increase the speed limit.

  3. REM permalink
    November 26, 2020 7:43 pm

    It’s probably so you don’t hit the abandoned, dead battery EV on what used to be the hard shoulder, quite as hard. Other than that, who gave Highways England permission to do this? Can we have a name?

  4. Lorde late permalink
    November 26, 2020 7:47 pm

    What a load of bol@/:ks.

  5. Peter F Gill permalink
    November 26, 2020 7:49 pm

    I recall that the 70 limit was introduced with the aim of saving fuel in a past oil crisis. This time politically it would be no more than virtue signalling by people who have been described in guarded terms by CheshireRed. Pity that CR did not really say what he or she really thinks.

    • Adam Gallon permalink
      November 26, 2020 8:30 pm

      No, the 70mph limit, was introduced after AC cars in 1964,was caught testing the performance of its 4.2 litre V8-engined Cobra up the M1 at 183 miles an hour!

      • Adam Gallon permalink
        November 26, 2020 8:32 pm

        No, the 70mph limit, was introduced after AC cars in 1964,was caught testing the performance of its 4.2 litre V8-engined Cobra up the M1 at 183 miles an hour! A 50mph limit was introduced during the 1973 oil crisis.

      • ThinkingScientist permalink
        November 26, 2020 8:43 pm

        It was their Le Mans car and they calculated it clocked 185 mph.

        The 70 mph speed limit wasn’t actually introduced until 1967, 3 years later, by Labour MP Barbara Castle.

        The oil crisis of 1973 resulted in the speed limit being reduced to 50 mph. Then to save fuel, not to save the planet.

      • Peter F Gill permalink
        November 26, 2020 8:44 pm

        Yes, I got that wrong Adam. By the way I used to live in Thames Ditton where AC cars were made. However, it wasn’t me in that car. I always stay strictly to any limit governments may impose for whatever reason. Similarly you can imagine that I always comply meekly with whatever instructions those thoughtful folks in Whitehall tell me to do. I checked and in the 1973 oil crisis a temporary maximum national speed limit of 50 mph was introduced.

      • Gamecock permalink
        November 27, 2020 1:14 am

        The AC Cobra was aerodynamically limited to 155 mph. That’s why Shelby had Pete Brock design the Cobra Daytona.

        “No, the 70mph limit, was introduced after AC cars in 1964,was caught testing the performance of its 4.2 litre V8-engined Cobra up the M1 at 183 miles an hour!”

        NFW. You could toss an AC Cobra out the back of a C-130, and it still wouldn’t do 183.

  6. It doesn't add up... permalink
    November 26, 2020 8:02 pm

    Presumably the main aim is to increase the income from speeding fines. We already have very extended areas where speed limits are rarely above 60mph. Anywhere they are “upgrading to smart motorways” it’s 50mph – and there are several other sections where such low limits apply, such as the Swansea end of the M4. Most of the smart motorway sections they play with the train set and very rarely set anything above 60mph limit. So it’s not like they don’t already have a ton of data they could mine.

    Of course, for Teslas in limp home mode, 60mph is probably too fast.

  7. November 26, 2020 8:06 pm

    To cut emissions even further … ALL vehicles should be proceeded by a man (sorry I mean a gender neutral being ) with a red flag – ‘Flaggers’ (this also solves the unemployment problem & reduces obesity), at these speeds no need for brakes (just a chock to put under a wheel) solves the harmful brake-dust particles.

    There is already a company song to keep the ‘Flaggers’ spirits up –

    • November 26, 2020 9:12 pm

      Hey! I was going to write that about t’t man w’it red flag like! 🙂

    • November 26, 2020 9:15 pm

      This scheme would also remove the need to fix potholes, thus saving the treasury another fat bundle of notes.

  8. Harry Passfield permalink
    November 26, 2020 8:11 pm

    This was dreamed up by the same lame-brains who came up with the idea that electric toasters and kettles (for instance) should be limited to 2kW (from their 3kW) to save energy.

  9. Paul Wilson permalink
    November 26, 2020 8:28 pm

    More anti-car garbage from the Govt.

  10. Joe Public permalink
    November 26, 2020 8:41 pm

    Perhaps we’ll soon see the headline:

    “Motorway speed limits to be increased to 90 mph in bid to increase Treasury receipts from fuel duty plus its 20%VAT”

    • ThinkingScientist permalink
      November 26, 2020 9:36 pm

      Most weekday evenings down the M3 the outside lane is clocking a steady 80 – 85 mph. ITs pretty normal.

      With all the announcements, I think Joe Public might start to get a tad ticked off in the not too distant future.

  11. Shoki Kaneda permalink
    November 26, 2020 8:49 pm

    Did Jimmy Carter influence this? He was obsessed with 55, both speed limit and thermostat setting.

  12. November 26, 2020 9:08 pm

    Beyond stupid. So you reduce speeds by about 15%, so cars are on the road for up to 15% longer. This could lead to more congestion and higher emissions.
    17% seems rather a lot for a relatively small reduction anyway.

  13. November 26, 2020 9:10 pm

    If the climate zealots are so worried about the 410ppm atmospheric concentration of CO2,(a historical low only ever seen one time before in the Ordovician since when it has ALWAYS been significantly higher), should they not perhaps ponder the 40,000ppm each of them exhales with every worthless breath?

    Maybe we should hold a national hold your breath competition inviting all and sundry from among the green zealotry to compete with prizes for those who hold their breath the longest…….

    • Is it just me? permalink
      November 26, 2020 9:44 pm

      Let’s start with Bozo (the clown) Johnson. Challenge him to a month without breathing. Put it on Netflix and get 50% of the proceeds to fund the NHS. Millions would pay. I guarantee it – especially when he turns purple and passes out.

    • yonason permalink
      November 27, 2020 8:34 am

      Now THAT’S how to “capture” carbon!

  14. November 26, 2020 9:17 pm

    The government insists on keeping reminding us just how stupid and uneducated they all are.

  15. November 26, 2020 9:35 pm

    Are our Politicians up to the job? It seems they are not. Mind you, it is said that the CO2is rather lower that it should be to keep our green land.

  16. Is it just me? permalink
    November 26, 2020 9:47 pm

    We’ve Brexited (well, let’s see). Locked down for months – our national motivation is now at rock bottom and our economy about to tank. So, let’s put the speed limits down so we can go even slower. At this rate – we’re likely to be overtaken on the global productivity ladder by just about every nation on earth. Britain, the wheezy kid bringing up the rear of the field on school sports day.

    • yonason permalink
      November 27, 2020 8:31 am

      “We’ve Brexited” – Is it just me?

      I guess your “betters” thought that the EU wasn’t ruining the UK fast enough?

  17. tokalo permalink
    November 26, 2020 10:13 pm

    I think is the first time I disagree with Paul. I find driving in the 50 mph zones (for “upgrading to smart”) on motorways rather relaxing. Because of the average speed cameras, nobody can push to go faster than the car ahead. So everyone settles down and is forced to drive sensibly.
    Bunching occurs where cars have driven too close to the vehicle in front at too high a speed (or where one of those self-centred so-and-sos hogs the middle lane).

    • slingshot permalink
      November 28, 2020 6:21 pm

      I agree, Tokalo. Through those 50mph areas, cruise control takes over and switches off my mind and concentration. Now isn’t that a good safety feature?

  18. Devoncamel permalink
    November 26, 2020 10:28 pm

    As soon as the Germans put the same limits on all of their autobahns I’ll accept it.

  19. Steve permalink
    November 26, 2020 10:50 pm

    Highways England are the people who invented smart motorways. Very often it has been run by female civil servants who have never driven anything more than their husbands mad.

  20. bobn permalink
    November 26, 2020 11:41 pm

    In order to compensate i now burn as much of my rubbish as is flammable – just to improve the the air balance and reduce my stress levels. Try it, a good blaze while saying take that you XXXXXXXXs is extremely calming. 😉

    • Graeme No.3 permalink
      November 27, 2020 12:28 am

      Don’t they burn rubbish in Germany, Denmark and Finland and possibly elsewhere in the EU? All classified as green.
      Also in Singapore where they have little room for rubbish dumps.

    • Paul H permalink
      November 27, 2020 11:02 am

      So do I! Burning old fence sections of late is such good fun, after the BBQ has finished. I have no inhibition whatsoever in lighting up outside, it’s so therapeutic, as you allude to.

  21. November 27, 2020 12:50 am

    The AA is a PLC, apparently and the R.A C. is owned by Aviva – the insurance company. Speak up for the motorist? Unlikely. Like most companies they seem to be profit driven, not for their members.

    • Gerry,England permalink
      November 27, 2020 10:12 am

      The days when the Automobile Association and the Royal Automobile Club represented motorists are long gone along with the use of their full names. In carrying out traffic consultations by law the Road Haulage Association and the Freight Haulage Association must be included but years back I got the admission from them that they did not have the capacity to study all of the proposals they get sent every week. Sadly, the unpleasant cyclists groups do all seem to be able to respond as they probably receive taxpayer cash to keep them going in the same way that the EU pays environmental groups to object to its proposals and therefore give it a reason to do what the econuts want.

  22. Gamecock permalink
    November 27, 2020 1:03 am

    History doesn’t repeat, but it often rhymes.

  23. Peter permalink
    November 27, 2020 2:44 am

    “Highways England estimates that a 60 mph speed limit on the motorway could cut emissions by as much as 17%.”.

    When I saw this, my BS-sensor went off immediately. I would like to see how they got to this number. I hope their reasoning is more intelligent than (70-60)/60*100%.

    • Tricky permalink
      November 27, 2020 7:46 am

      The report has totally missed the point – travelling slower requires less power as there is less drag, so you use less fuel. Drag is proportional to speed raised to a power – at least 2 and possibly 3. If you use 2, then the saving is about the 17% quoted.

      Will the electric cars on green energy still be able to go at 70???

      • Peter F Gill permalink
        November 27, 2020 7:14 pm

        I seem to remember that its 3 for boats. However, with all the flooding that AGW fanatics assume is down to man made climate change maybe it applies to cars as well on flooded roads.

    • November 27, 2020 9:11 am

      (70-60)/60*100% =16.7%
      That is the reduction in the number of vehicles the motorway can carry when full.
      This then gives an equivalent reduction in fuel use.
      Achieved by making transport for all more difficult.

  24. yonason permalink
    November 27, 2020 8:24 am

    I have a Hyundai Sonata. When on the expressway, I get my most efficient mileage at around 75 mph, as indicated by the mpg readout on my speedometer. At 60 it’s better than city traffic, but noticeably less efficient than at the higher speed. I can’t imagine most modern cars not being able to perform better at faster than 60 mph.

  25. November 27, 2020 8:52 am

    Oh to be able to go back to the 1960s. NO motorway speed limits; NO VAT; NO wokeness; NO PC crap; NO hate crimes; NO speech crimes – and glorious music.

    • Peter F Gill permalink
      November 27, 2020 9:45 am

      @Fizzy fellow: And the dawn of the E type to take advantage of those unlimited roads!

    • Russ Wood permalink
      November 27, 2020 3:57 pm

      In the mid 1960’s it was the only time I was ever able to ‘do the ton’ on the new M1. I was driving a friend’s Dad’s car to a concert, because my little Fiat 500 (original!) was only able to do 60 mph downhill with a following wind! (AND it sounded like a neurotic sewing machine!)

  26. Gerry, England permalink
    November 27, 2020 10:26 am

    An internal combustion engine is at its most efficient at the point where it produces the maximum torque. Cruising at this point will give the best MPG. The revs at which that happen will vary across vehicles and vehicle type. My 1000cc V-twin Moto Guzzi hits that point at 80MPH and will give 65-70 MPG. My diesel van has this point at 60MPH strangely enough. Motorways are intended to move traffic at higher speeds than ordinary roads but with this you could go faster on a dual carriageway, just as fast on unrestricted roads, or even faster given there won’t be camera everywhere.

    • Gamecock permalink
      November 27, 2020 1:16 pm

      “Cruising at this point will give the best MPG”

      Not so. Aerodynamic drag becomes a significant factor at over 45mph.

      • Clyde Spencer permalink
        November 30, 2020 3:33 am


        To be more precise, air resistance increases with the cube of the speed, and rolling resistance increases with the square of the speed. If fuel efficiency were the only concern, then designers would probably limit cars to 45MPH. As it turns out, in general, the MPG increases steeply at low speeds, reaches an optimum at some variable speed (depending on many factors, including the coefficient of drag), and then starts to decline slowly (at first) after the optimum.

        Auto manufacturers generally try to compromise between performance and fuel economy. One way of doing that is by a selection of gear ratios in the transmission and differential. Unlike politicians, automotive engineers are generally smart. A problem is that when the highest transmission gear ratio is decided on, it reflects the prevailing highway speed (and probably the recognized tendency for people to push the envelope of the law).

        In the US, before the Arab Oil Embargo of the early-’70s, cars generally got their peak gas mileage around 65MPH. The reduced 55MPH freeway speed limits required the cars already on the road to drive at speeds that gave poorer fuel economy, probably about equivalent to 75 to 85MPH.

        Forcing cars to drive slower than they were designed to cruise at will result in more CO2 for a given distance, rather than less!

    • It doesn't add up... permalink
      November 29, 2020 9:56 pm

      Perhaps if you are driving a boxy Range Rover or EV SUV, but a good aerodynamic design has very little drag. The equation for power needed to offset drag is


      A good modern car has a CdA of about 0.5m^2; the density of air, ρ, is 1.225kg/m^3 at standard temperature and pressure, which gives about 0.3v^3 as the required power. 50mph is about 22.4m/sec; 80mph is about 35.8m/sec, so drag would require power of just 13.7kW to offset at 80mph.

      Engines operate at their most fuel efficient when providing a particular combination of torque and engine speed.

      The map of engine efficiency is in fact the real key to optimising fuel consumption. Modern diesels are designed to cruise at a continental 130kph, or about 2,300rpm in top gear. Going faster will exact an increasingly severe fuel penalty mainly as a result of suboptimal engine conditions, and only secondarily from drag and rolling resistance and transmission losses, but going slower will also run into a less fuel efficient engine regime, offsetting the savings on losses. In an automatic transmission losses are much higher at lower speeds – there is significant slippage at speeds below 55mph (which is why that speed was chosen for the fuel saving limit in the US during the 1970s oil crisis).

  27. David permalink
    November 27, 2020 11:57 am

    Motorists are more likely to get drowsy and cause accidents at 50.

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