Safe Speed Forums

http://politics.guardian.co.uk/homeaffa ... 46,00.html

Speed limit crackdown to cut emissions

Leak reveals climate change plans

David Adam, environment correspondent
Monday November 14, 2005
The Guardian

Ministers are planning to crack down on motorists who speed on motorways in an attempt to meet government targets aimed at reducing Britain's emissions of greenhouse gases.

Officials acknowledge that any move to force the 15 million motorists who currently exceed the 70 mph speed limit to slow down would be "politically sensitive", but they say it would save significant amounts of carbon dioxide pollution. Engine efficiency falls quickly beyond 70 mph.

The proposal is among dozens of new measures outlined in a confidential government review of its policies to tackle climate change, a copy of which has been obtained by the Guardian. The review was ordered in September 2004 because ministers were struggling to meet their pledge to cut UK emissions of carbon dioxide by 20% by 2010, a commitment restated in this year's election manifesto.

It was drawn up by Elliot Morley, minister for climate change at the Department for Environment, Food and Rural Affairs, and is being discussed by the cabinet committee on energy and the environment, which is expected to publish a revised version early next year.

Marked restricted, the review document says: "The government needs to strengthen its domestic credibility on climate change. The revised programme must therefore set out a comprehensive and ambitious package of policies to deliver the manifesto commitment and achieve our domestic goals. We must not underestimate the scale of the challenge."

Existing policies set out in 2000 to cut carbon dioxide emissions are falling well short, it adds. "We need to do about 75% more in around half the time."

The review lists 58 possible measures to save an extra 11m-14m tons of carbon pollution each year, which it calls the government's "carbon gap". One of the options, a new obligation to mix renewable biofuels into petrol for vehicles, was announced last week. Stricter enforcement of the 70 mph limit, the document says, would save 890,000 tons of carbon a year - more than the biofuels obligation and many other listed measures put together.

Andrew Howard of the AA Motoring Trust said: "They would have to win a lot of hearts and minds to convince the public that this wasn't just a revenue generating exercise. It also raises some big questions about whether speed enforcement for environmental rather than road safety reasons should be an offence for which motorists get points on their licence."

The most effective steps, the review says, are pollution caps imposed on industry under UK and European carbon trading schemes. Other proposals include mechanisms to increase electricity generation from offshore wind turbines and combined heat and power systems, stricter enforcement of building regulations and linking winter fuel payments for pensioners to energy efficiency measures.

It also weighs up what it calls "politically difficult" options, which include road-user charging, changes to speed limits, high-speed rail links and reintroducing double British summertime - where the clocks go forward two hours in spring.

The document concludes: "Even if we implement all the front runner and emerging policy options, we may only just fill the carbon gap." Other measures will be needed, it adds. Controversially, it proposes that carbon allowances and credits from emission trading schemes could count towards the 2010 target, though it concedes this "may raise presentational issues".

A Defra spokesman said a variety of options were being discussed.
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Just the right comment from Andrew Howard. (for once).

This has been making bits and bobs of news all day. Darling was ambushed on the subject on the Radio 4 Today Programme this morning. He insisted that speed limits should only be set on safety grounds. Interesting. I've captured the audio. You can listen again from the Today Programme web site.

The DfT press office say that the document should never have reached the public. Also interesting.

We have the making of a jolly good inter-departmental row here, with the DfT possibly being forced into admitting that increasing motorway speed enforcement might be dangerous.

I've been stirring the pot.

Now let's sit back and await developments...

edited to add: Just to make it clear, the leaked document came from DEFRA.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Do they know what they are talking about ?

The impact on emissions of traffic calming and other deliberate measures to increase congestion far outweigh any gains here.

Clearly 'engine efficiency' doesn't.

But overall efficiency does fall quite rapidly at higher speeds and 'above 70mph' is likely to be a reasonable statement.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

It might be worth doing a pollution check on two roads. One with humps, one without with similar traffic levels and profiles. I would love to see the result show massive amounts of pollution due to these infernal humps They also don't mention how much extra pollution they cause in the extra frequency one has to change suspension and brakes. Having just had to fork out over a grand for a complete set of shocks ( couldn't afford to put replacement ohlins on as they were 2k ) because two opposite corners were wrecked; I'm still livid enough to help with stirring.

If you have a car with one of those fancy trip computers that can show instant mpg - check it next time you are on a "humped" road. The consumption is terrible. Mine drops to 8 mpg when in first/second gear.

Personally I don't believe all this global warning CO2 nonsense - its just an easy way to fool people into accepting higher taxation.

Hmmm... Really?? Doesn't gel too well with http://news.bbc.co.uk/1/hi/england/devon/4436040.stm

Maybe they need to do a bit of "joined-up government"!

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"Politicians are the same the world over... We build bridges where there aren't any rivers." - Nikita Kruschev

I would agree that fuel consumption rises quite rapidly due to the increased power requirement, but the efficiency doesn't fall rapidly, indeed it may initially increase. There are a lot of factors to consider here, but such vague language from DEFRA suggests a lack of understanding.

Hava a look on the ABD website- there's a quote from an eminent scientist which basically says "if every petrol-engined vehicle were banned, the net result globally would be a drop of 0.5% (yes, half a percent) in CO2 levels "- in other words, negligible.
The main culprits are industry etc, whilst the villain of the motoring world is the large diesel engine, which (although comparitively low in certain emissions) pumps out shed-loads of one of the world's deadliest carcinogens (so much for green friendly buses).

And what about the recent (ish) report that inter city trains produce more pollution per passenger than cars.

Quite right.
Again, quoting a scientist on the ABD site:
"A family of four travelling by car is about the most eco-friendly you can get".

As I understand it, the actual thermal efficiency of a petrol engine is greater at high power than at low power, because throttling the intake to reduce the amount of air entering the engine effectively reduces the compression ratio. (You have to throttle the air if you reduce the amount of fuel going in, otherwise the mixture will be so lean it won't burn when you spark it.)

Diesel engines compress a full charge of air with every stroke, they just inject less fuel at low power (which will burn anyway because the compressed air is so hot). So they maintain their efficiency at low speed which is why they generally do better than petrol engines for a given maximum power output.

Turbo engines (of both types) change the rules a bit but the principles are broadly the same.

Of course as you increase speed the air resistance goes up proportional to the square of the speed, so ultimately the efficiency of the car in terms of mpg goes down. But in terms of engine efficiency going down... that's total garbage.

They are using 'efficiency' in the physics sense at the system level.

i.e. The ratio of useful work performed by a device or system to the total energy input. (OED)

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

"Useful work" isn't a measure of distance - I'm getting more useful work out of the enngine when my car goes faster!

Energy cost per passenger-mile isn't strictly a measure of efficiency as it is not unitless.

This is getting excessively pedantic for me. The original article was written by a journalist. We have every right to demand a fair standard of english from journalists, but probably not a high standard of technical understanding (unless they are specialised). I agree that the original wording was clumsy - even incorrect. But I understood exactly what was intended. Not only that but I found the intended claim to be reasonable.

Personally I accept 'mpg' as a useful measure of 'fuel efficiency' of various vehicles under various operating conditions. With standardised operating conditions we have a useful way of comparing one vehicle with another.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Well, here's a crazy idea

Instead of screwing more revenue out of us when we buy new cars, lets ditch the special car tax on tax and replace it with a tree fee

Say, £500. This would buy 5 reasonable size trees that could then be planted to offset the carbon emissions for each new car purchased.

Give it 10 years of that, and we would have some bloody good forests sucking up all that nasty CO2 and giving us lovely fresh oxygen

Just my 2 cents worth

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"Are you sh**ing me?"
"John Spartan, you are fined one credit for a violation of the verbal morality statute."

That would be far too sensible and it assumes that the Government actually care about CO2 levels. They are just looking for justification to fleece the 70% of motorway users that exceed the 70mph limit. Rigid speed limit enforcement on motorways is a potentially huge cash cow for the Government and will provide the revenue they need to research and develop innovative new ways of taxing people on their mobility while doing nothing whatsoever for the environment.

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“For every complex problem, there is a solution that is simple, neat, and wrong.” - H. L. Mencken

If they are that worried about wasted fuel they should take away road tolls.
How much fuel is burnt stopping to cross the severn, the thames and that nice little M6 section.


However we are talking about making criminals out of people for wasting fuel.
If I drive my toyota at 110 I can get better economy than my sisters 2.5 turbo deisel landrover at 60.

It would be simpler to put all road taxes on fuel. It is back to the same old rusty tool box and get that same old dirty hammer and bash the same old motorist.... that'll fix it.... propper job!

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Speed limit sign radio interview. TV Snap Unhappy
“It has never been the rule in this country – I hope it never will be - that suspected criminal offences must automatically be the subject of prosecution” He added that there should be a prosecution: “wherever it appears that the offence or the circumstances of its commission is or are of such a character that a prosecution in respect thereof is required in the public interest”
This approach has been endorsed by Attorney General ever since 1951. CPS Code

How about a mass protest? We'll all sit at 70 but at 4th or 3rd gear burning as much fuel as possible until they see the utter stupidity of it. Besides Mways enforced with cameras are a nightmare as the traffic bunches up dangerously. Once they Mway death rate goes up will they be happy then? Will they be happy when lots of people stop using motorways and use A roads/dual carriageways knowing that the accident rate on these roads is higher?

It now appears (Today, R4) that the government is "sidelining" (i.e. dropping) this proposal as fast as they can. Darling was very uncomfortable about it yesterday, and the message has got through that it's politically a non-starter. Be very surprised if this appears in any bill in this parliament.

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Keep right on to the end of the road ...

Enforcement of the 70mph limit will lead to more bunching and the like.
Fuel consumption, and therefore emissions, is much higher when a vehicle is continually accelerating and decelerating than when it is driven at a constant speed - even better if the engine output is held constant.

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler