60 mph motorway limits

[Alf27]

https://www.bbc.co.uk/news/uk-england-54130862

[doebag]

Well in a world where HGV's run around at 56mph, and a lot of car drivers are scared to do more than an 'indicated' 60, this could be interesting.

[Ruperts Trooper]

The sections chosen are often so congested that more than 60 is just not possible - of course, when there's less traffic there's less NOx so it's something of a pointless experiment.

[Glenn A]

The sections chosen are often so congested that more than 60 is just not possible - of course, when there's less traffic there's less NOx so it's something of a pointless experiment.

Could be the thin end of the wedge, as there are plenty of car hating local authorities, Green campaigners and police forces who see this as a way of making more money from speeding fines. What's to say the next step will be too many people are speeding on quiet motorways, so the speed limit on the A74(M) should be cut to 60 mph. Also the gradual switch to electric vehicles and the decline of diesel will make the environmental argument less valid in years to come.

[DB617]

What, the speed limit is being reduced on *more* congested trunk roads? When will they realise they're mostly chasing a fallacy?

[Big L]

Is there any published data that actually supports this course of action? Specifically, is free-flowing traffic at 70 worse for emissions than stop-start or crawling rush-hour traffic? Or is it just the case that high pollution = we must do something = speed limits are something?

[c2R]

Is there any published data that actually supports this course of action? Specifically, is free-flowing traffic at 70 worse for emissions than stop-start or crawling rush-hour traffic? Or is it just the case that high pollution = we must do something = speed limits are something?

The studies prove that free flowing 60 produces less NOx than free flowing 70; which is what is being trialled.

Of course, a better policy would be to not build housing right up to trunk road highway boundaries.

[Truvelo]

But isn't most of the particulate emissions from larger vehicles who's top speed is limited to 56 which these proposals won't affect.

[Glenn A]

America had its notorious 55 mph speed limit introduced during the 1974 energy crisis and the reduction in fuel consumption was about one per cent, while the effects on the environment were very limited. What did reduce fuel consumption and emissions were a switch to cars with smaller engines, phasing out leaded petrol and emissions control equipment in car engines. By the mid eighties, the speed limit was seen as a joke, not widely enforced in many states and widely ignored and was steadily lifted.

[Big L]

Is there any published data that actually supports this course of action? Specifically, is free-flowing traffic at 70 worse for emissions than stop-start or crawling rush-hour traffic? Or is it just the case that high pollution = we must do something = speed limits are something?

The studies prove that free flowing 60 produces less NOx than free flowing 70; which is what is being trialled.

Of course, a better policy would be to not build housing right up to trunk road highway boundaries.

So "no" then?

[Phil]

Is there any published data that actually supports this course of action? Specifically, is free-flowing traffic at 70 worse for emissions than stop-start or crawling rush-hour traffic? Or is it just the case that high pollution = we must do something = speed limits are something?

The studies prove that free flowing 60 produces less NOx than free flowing 70; which is what is being trialled.

Of course, a better policy would be to not build housing right up to trunk road highway boundaries.

So "no" then?

What part of the phrase "The studies prove that free flowing 60 produces less NOx than free flowing 70; which is what is being trialled" is so hard to grasp.

If the stated goal is a reduction in NOx levels and you are not going to reduce traffic volumes the the proposal is sceinfifically sound.

Granted there may be other undesirable outcomes* - but that is not relevant to achieving specific scientific goal of less NOx levels.


* A decade ago the Government was actively encouraging the sales of diesel cars as they produce less CO2 emissions per litre of fuel used than the same model fitted with a petrol engine. The fact that diesel engines produce more NOx emissions than petrol was ignored - the focus was on reducing CO2.

[mark3evo]

hmm..

look at this, if only the Government had the monitoring equip back in the day

what with introduction of Clean burn diesels we must be continuing to reduce NOX

https://notalotofpeopleknowthat.wordpre ... s-to-fall/

[Glenn A]

Ten years in the future, when diesel vehicles are far less common and hybrid and electric technology is widespread, what will the excuse be then?

[Big L]

What part of the phrase "The studies prove that free flowing 60 produces less NOx than free flowing 70; which is what is being trialled" is so hard to grasp...

I asked a specific question. You can tell that from the fact I started it with the word "specifically".

So, while c2R may well have made an accurate statement, it wasnt an answer to the question I asked.

If I asked, specifically, "are elephants bigger than mice" and someone replied telling me that "elephants are bigger than cows", that's factually accurate but doesn't answer the question now does it?

Not too hard to grasp?

[c2R]

I believe that's the purpose of the trial, given the previous statement that elephants are bigger than cows

And I don't think there's some big conspiracy to reduce speed limits to a crawl for its own sake, or to gain as many fines as possible - merely that they are trying to address the health disbenefits experienced by masses of NOx in the air - caused by the dual previous policies of encouraging diesel cars to reduce CO2 emissions and allowing practically uncontrolled planning to build up to the edges of major strategic roads.

[Bryn666]

Ten years in the future, when diesel vehicles are far less common and hybrid and electric technology is widespread, what will the excuse be then?

Electric and hybrid technology will not be widespread. The infrastructure to allow this switch should have been in place 5 years ago to allow that.

[Bryn666]

I believe that's the purpose of the trial, given the previous statement that elephants are bigger than cows

And I don't think there's some big conspiracy to reduce speed limits to a crawl for its own sake, or to gain as many fines as possible - merely that they are trying to address the health disbenefits experienced by masses of NOx in the air - caused by the dual previous policies of encouraging diesel cars to reduce CO2 emissions and allowing practically uncontrolled planning to build up to the edges of major strategic roads.

Indeed, everything is now a conspiracy to people. There can't possibly be a simple reason for doing something. Heaven forfend people have to drive slower for 3 miles on the M602, I mean, it's the end of democracy as we know it.

[Conekicker]

The air quality figures for the "bad" sections, when were they taken, pre-covid or in the last few months? What are they now? If, due to covid, they are now acceptable, where is the valid reason to delay traffic through some or all of these sections?

One could equally apply the same argument to the forthcoming CAZ in many cities. For example, in Sheffield traffic is still far less than pre-covid, so one wonders what the air quality numbers are today. If they don't justify a CAZ, why install one?

[Bryn666]

If the school run in Bolton is anything to go by, all the air quality improvements experienced over the last six months will be wiped out in a few weeks.

[Truvelo]

No one can predict how quickly EV's will become widespread but in ten years time we should be seeing solid state batteries which will be a game changer in their uptake. There is a lot of pent up demand for electric which is being restrained by costs and current battery technology. I myself would like one but 300 miles per charge is woefully insufficient for my needs.

Anyway, regarding these speed limits what will be the threshold of EV uptake to revert back to 70? If 50% of cars and light vehicles are electric then the extra emissions from the remaining ICE powered cars returning to 70mph will be outweighed by EV's and of course, ICE's are still getting cleaner so a lot of the diesels on the roads now will be in the breakers yard in ten years time.