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Entirely unashamed anti car propaganda, and the more the better.

Urban speed limits here have just been reduced to, depending on the road, as low as 20, 30, and 50. There is no noticeable hindrance to the traffic flow.

From the DGT twitter:
  • 20 km/h on roads that have a single lane with one way traffic and with a raised path/sidewalk.
  • 30 km/h on roads with one lane in each direction reduced from 50km/h.
  • 50 km/h on roads with two or more lanes per traffic direction. This speed limit remains the same except for vehicles carrying heavy or dangerous goods which must reduce their speed to 40 km/h.

Unfortunately there's a lot of people, usually Brits, complaining about it. Some are convinced that the speed limits on the motorways has also been dropped to 50. I've even heard people saying it is impossible to go this slowly, because, "my car can't go that slowly."
 
I've even heard people saying it is impossible to go this slowly, because, "my car can't go that slowly."

Pretty much this has been used as an argument on here; if I recall correctly something about cars' gears making 20mph too difficult to drive at.

The other one is that it will be dangerous for people to drive at 20mph because they'll be watching the speedometer instead of the road.
 
I said (correctly) that it was difficult to set cruise control for 20 - as it doesn't become active until just below that speed

Others lambasted me for using cruise control at such a speed and I should be using the speed limiter instead. We agreed to differ
 
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And I said (quite correctly in the case of my automatic bike and indeed many cars, though not all), that 20 mph speeds can be more polluting than 30 mph.
 
And I said (quite correctly in the case of my automatic bike and indeed many cars, though not all), that 20 mph speeds can be more polluting than 30 mph.
I have heard this, but never seen the receipts. Is there a reputable study?
 
I have heard this, but never seen the receipts. Is there a reputable study?
Well, I guess there'll be differences automatic and manual vehicles, but traditionally 30 mph on 4th gear tends to be sweet spot for the lowest consumption and and pollution levels in urban driving (not necessarily the sweet spot ovreall at any speed, of course).

It is likely newly manufactured cars are starting to reflect the trend of decreased speed limits in urban areas across Europe, but older manual cars are far from efficient at 20 mph.

My 400cc automatic bike consistently returns far, far worse fuel consumption figures at 20 mph than at 30. Though of course that might not necessarily be the same for other automatic single gear bikes.
 
I have heard this, but never seen the receipts. Is there a reputable study?
According to this article in the Guardian, the Energy Savings Trust suggests the best fuel economy is achieved by driving between 55 and 65 mph so perhaps we should ensure that all obstructions are removed from the roads and all speed limits are increased to 65mph everywhere so this is possible! :D

 
Well, I guess there'll be differences automatic and manual vehicles, but traditionally 30 mph on 4th gear tends to be sweet spot for the lowest consumption and and pollution levels in urban driving (not necessarily the sweet spot ovreall at any speed, of course).

It is likely newly manufactured cars are starting to reflect the trend of decreased speed limits in urban areas across Europe, but older manual cars are far from efficient at 20 mph.

My 400cc automatic bike consistently returns far, far worse fuel consumption figures at 20 mph than at 30. Though of course that might not necessarily be the same for other automatic single gear bikes.
Even if all this is true - so what?

Anyone who actually cared about pollution would just drive less instead of waffling on about gears.
 
The debate, such as it is, seems to be discussing driving at 20mph. The new speed limits here are, of course, in kph. Driving at 20kph means, in my car, driving between 1st and 2nd. Of course it is doable. Whether it is a good idea from the point of view of increased pollution is a different matter.
 
It doesn’t increase pollution, it lessens it but anyway reducing a speed limit is a traffic calming measure to save lives being lost in accidents, rather than lessening emissions
Do you have any studies to back that up?

Before we waste any more time on this issue, you are aware that all internal combusition vehicles, irrelevant of type of transmission, number of gears, or size engine, have speed sweet spot for the lowest fuel consumption (and therefore pollution), that is never, ever the lowest speed possible of the vehicle, right? Indeed, the best results are usually achieved in the 45-55 mph range.

This is of course irrelevant to the argument of urban driving, as those speeds are far too fast. But it proves to anyone who might have any doubts that extremely low speeds are in no fucking way the most fuel-efficient way to cover distance by any given bigger than a light 50cc scooter.
 
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