# 20mph speed zones



## just jim (11 Dec 2009)

20mph speed zones cut road injuries by 40%, study says

Roll it out.


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## dellzeqq (11 Dec 2009)

indeed. And the most interesting thing about the article is that it is about what has happened, not what some bright spark theorised might happen.


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## GrasB (11 Dec 2009)

Unfortunately there's precious little real information in that article, it's more like a blurb. I'm also a little circumspect about the department this research has come from but that doesn't mean the research isn't valid.

Much more interesting would be to see where the areas were that 20mph limits where applied & if this lasted longer than an 'novelty period'. There's no point in blanket 20mph speed limits where it has no relevance as all you'll do is alienate the driving population & devalue the importance of 20 limits when they really are appropriate. That said I'm for 20mph limits in residential areas.


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## dellzeqq (11 Dec 2009)

http://www.tfl.gov.uk/assets/downloads/20-mph-zones-and-road-safety-in-london.pdf

this study was commissioned by TfL and the writers point out repeatedly that London is a special case, as car ownership is lower, and the use of public transport is higher. However studies from around the UK all bear out the conclusions - not least the study in Hull.

The areas are mostly in zone 2 - althought the greatest single concentration is in Kingston. The effects seem to be permanent.


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## numbnuts (11 Dec 2009)

> I'd like to see the arguments against...


Not against, but car engines were not built around a 20mph speed limit would they not produce more harmful emissions as the engine would not reach it’s full working temperature.


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## GrasB (11 Dec 2009)

The engine will reach full operating temp, low speed + higher rim = slightly faster warm up in general but it'll mean people are driving in lower gears so thus lower fuel economy & more emissions.


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## dellzeqq (11 Dec 2009)

depends how they're driven. Given the frequency of junctions on residential roads, accellerating from zero to 30 and then braking again every few hundred yards will be less efficient, and noisier. 

The study reports that 20mph zones are popular with residents.


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## GrasB (11 Dec 2009)

Noise has way to many factors, the gearing, the engine, how good the driver is at throttle control, amount of engine vibration at low rpm etc.. 

On residential roads I rarely get up to 30 anyway, there's to much going to. But then again, I view the speed limit as the maximum NOT a target to get to ASAP.


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## Davidc (11 Dec 2009)

Bring back the man with the red flag.

Motor vehicles in urban areas are dangerous. Appropriate speed limits are the only way to mitigate that danger. Why does the limit have to be as high as 20mph?


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## snorri (11 Dec 2009)

GrasB said:


> but it'll mean people are driving in lower gears so thus lower fuel economy & more emissions.


Car manufacturers are failing to design for our 21st century road conditions.


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## joolsybools (11 Dec 2009)

Have you seen the comments in the 'have your say'?

http://newsforums.bbc.co.uk/nol/thread.jspa?forumID=7334&edition=1&ttl=20091211122207

I think we need a few more pro-cycling comments in there please folks!


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## Dilbert (11 Dec 2009)

IMO narrow residential streets should be 10mph, wider residential areas 20mph (shopping streets out of town centre etc) with 30mph only for arterial routes in and out. 

I think if people were driving at a lower speed more consistently it would increase traffic flow and reduce emissions.

Also if driving was slower it might encourage more people to walk and cycle for short journeys which will have a beneficial effect on the environment.


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## thomas (11 Dec 2009)

> the 20mph speed is all well and good - however you still can kill some one at the speed.
> 
> whats is needed is that the pedestrians learn some road sense, i have too often had to break so not to hit a jaywalker who just darts out infront of me.


That's all well and good, but you don't need any formal training to walk to the paper shop.


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## just jim (11 Dec 2009)

joolsybools said:


> Have you seen the comments in the 'have your say'?
> 
> http://newsforums.bbc.co.uk/nol/thread.jspa?forumID=7334&edition=1&ttl=20091211122207
> 
> I think we need a few more pro-cycling comments in there please folks!



Speak Your Braynes candidate:

"The answer is not a lower speed limit, but less people on the roads, but if Labour are going to encourage tens of thousands to immigrate here every year, there will soon be no housing, no space, no jobs and even more people on the roads!"


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## gaz (11 Dec 2009)

GrasB said:


> The engine will reach full operating temp, low speed + higher rim = slightly faster warm up in general but it'll mean people are driving in lower gears so thus lower fuel economy & more emissions.


well if anyone cares about emissions and fuel economy then just stick it in 3rd and the car will be pretty much idling as your doing 20.


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## StuartG (11 Dec 2009)

I don't like 20 mph areas thinking myself the best judge of speed to which I should take full responsibility. However having just read the comments on the BBC site I am again reluctantly appalled by the mentality of some car drivers. To think was they say is bad - to publish it is mad.

I still don't think 20 mph zones are the sole answer. We need a programme to dramatically reduce car traffic in built up areas. In London we have a public transport system that can make many journeys redundant. Building up the StreetCar concept for the rest could clear our streets from the clutter that is a danger for pedestrians and cyclists. Why, it might even be safe for buses and StreetCars to do 30 mph in this new world ...


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## porteous (11 Dec 2009)

*Work life balance*

I agree with Stuart G, we need a total transport rethink. Lower speed limits AND less travel perhaps? We also seem to expect to drive for an hour to get to work. I rather like the French approach, where jobs go out to where people live , in the form of subsidised small (and large) factories, government offices, etc. If we really need to bump start the economy with public works why not rebuild some old railways to take trams and put in a REAL bicycle network while increasing local bus services? I drive a Volvo estate and hold car and bus licences as well as riding a bike, I would much prefer to use bikes more and the car less! British transport planning sems to have no rationale whatever, IMHO. Jobs to where people live, infrastructure projects to encourage local public transport and bicycle use! Sensible local speed limits, 20mph in narrow residential, or near schools, etc, 30 elsewhere. Big towns 40 on main arteries. Nothing wrong with motorways for major journeys.


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## StuartG (11 Dec 2009)

Be careful. Many of our cities had work in the middle with people living around. This is the best system for public transport with their 'star' networks. In London it is very easy to get from almost anywhere to the centre of London. In can be very challenging to go anywhere else.

It is also the worst system for vehicle traffic creating a natural congestion zone and making it worse by turning into a daytime parking lot too.

Whilst you and I would like to see a lot more cycling - realistically for many people public transport is the alternative to commuting by car. So centralising work is best?


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## Cab (11 Dec 2009)

Seems irrefutably true now that lower speed limits in urban areas save lives, and as the time taken to travel from A to B in towns is overwhelmingly governed by congestion, traffic lights and junctions, it isn't like anyone is really slowed down by this.

Lower speed limits and good enforcement will save lives. Ain't difficult.


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## StuartG (11 Dec 2009)

This is what worries me. Most of the residential streets around here with two lines of parked cars are hard to navigate at much more than 20 mph anyway. However even at that speed they obscure vision and ability to swerve so an ill timed dash out between cars puts you in death's lottery.

Whereas in the more leafy surburbs with drives and garages - then a 30 mph means 40 mph away from speed cameras.

Which would make the actual raw observations interesting. There is the danger of oversimplification in drawing broad conclusions especially as the law needs to be simple.

As a thought and a sop to the motoring lobby who cannot be ignored - might it be a bargain that we reduce residential limits to 20mph and in exchange increase motorway limits to 80mph albeit with higher penalties for exceeding (up to 90 fine & points, upto 100 automatic 2 year disqualification, over 100 lifetime disqualification). At least no pedestrians or cyclists would be endangered ...


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## marinyork (11 Dec 2009)

GrasB said:


> Much more interesting would be to see where the areas were that 20mph limits where applied & if this lasted longer than an 'novelty period'. There's no point in blanket 20mph speed limits where it has no relevance as all you'll do is alienate the driving population & devalue the importance of 20 limits when they really are appropriate. That said I'm for 20mph limits in residential areas.



I used to think like this but having lived on a 20mph zone I now see that there isn't this distinction. Motorists say this line but in reality are convinced that nearly all 20mph limits are "bogus". You can have a busy ped area many hours a day, a busy school and they'll come out with the same tired old line about why do we have to have 24hr 20mph zones and the ranting and raving goes on. Motorists support school 20mph zones as it doesn't threaten their world view, just splash a 20 zone for 2x30 minute periods and it is business as usual. If you have 20mph zones in even a small percentage of roads it starts to affect people's bad habits - the monospeed drivers, the aggressive drivers and so on.


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## jonesy (11 Dec 2009)

GrasB said:


> The engine will reach full operating temp, low speed + higher rim = slightly faster warm up in general but it'll mean people are driving in lower gears so thus lower fuel economy & more emissions.



Indeed, the AA are very keen to point this out, though for an organisation that is clearly so concerned about emissions they seem reluctant to mention the CO2 savings you'd get from reducing speeds on motorways, where a vastly greater proportion of total mileage is driven...


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## just jim (11 Dec 2009)

I like driving around at 20mph. It's less stressful. What's the hurry? Leave the house 5 minutes earlier if it matters that much.


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## addictfreak (11 Dec 2009)

Davidc said:


> Bring back the man with the red flag.
> 
> *Motor vehicles in urban areas are dangerous*. Appropriate speed limits are the only way to mitigate that danger. Why does the limit have to be as high as 20mph?



The motor vehicle itself is not dangerous, it becomes dangerous when you introduce people into the equation. Be they drivers, cyclists or pedestrians.


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## marinyork (11 Dec 2009)

addictfreak said:


> The motor vehicle itself is not dangerous, it becomes dangerous when you introduce people into the equation. Be they drivers, cyclists or pedestrians.



The motor vehicle is dangerous. It's the kinetic energy levels you can get upto easily. As Mr Scott says, you cannae change the laws of physics.


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## addictfreak (11 Dec 2009)

marinyork said:


> The motor vehicle is dangerous. It's the kinetic energy levels you can get upto easily. As Mr Scott says, you cannae change the laws of physics.



It wont go anywhere without a person in it, or a person interacting with it.


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## MacB (11 Dec 2009)

addictfreak said:


> It wont go anywhere without a person in it, or a person interacting with it.



not the point, it carries more kinetic energy when it moves, therefore is inherently more dangerous.


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## addictfreak (11 Dec 2009)

MacB said:


> not the point, it carries more kinetic energy when it moves, therefore is inherently more dangerous.




But as I clearly said, unless a person drives it, or moves it or causes it to move then its not dangerous.


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## dellzeqq (11 Dec 2009)

addictfreak said:


> But as I clearly said, unless a person drives it, or moves it or causes it to move then its not dangerous.


in that case can we take the wheels off, just to be sure?


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## Bay Runner (12 Dec 2009)

GrasB said:


> I view the speed limit as the maximum NOT a target to get to ASAP.



I agree!

I get fed up with annoyed drivers behind me in 20 mph zone thinking the speed limit does not apply to them. 

I don’t own a car but I drive my wife's now and again, driving round town with the speed limiter set at 30 mph, same again Mr. Important in his BMW zooms past looking at me as if I am a peasant for not breaking the law !!!! 

If 20 mph zones reduce deaths and injuries they have to be a good thing!


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## ComedyPilot (12 Dec 2009)

30mph is safe with competent, alert and responsible drivers. We're stuck on an island with thousands of the buggers that couldn't give a flying toss about anyone but themselves. So a lower speed limit will slow responsible drivers down, but will still see irresponsible tossers flouting it just as much as they do with 30's 40's and 50 limits.


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## addictfreak (12 Dec 2009)

dellzeqq said:


> in that case can we take the wheels off, just to be sure?




That would make it a big trip hazard and someone would still complain


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## jonesy (12 Dec 2009)

ComedyPilot said:


> 30mph is safe with competent, alert and responsible drivers. We're stuck on an island with thousands of the buggers that couldn't give a flying toss about anyone but themselves. So a lower speed limit will slow responsible drivers down, but will still see irresponsible tossers flouting it just as much as they do with 30's 40's and 50 limits.



But the conclusion of the research is that they do still improve safety.


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## GrasB (12 Dec 2009)

marinyork said:


> I used to think like this but having lived on a 20mph zone I now see that there isn't this distinction. Motorists say this line but in reality are convinced that nearly all 20mph limits are "bogus". You can have a busy ped area many hours a day, a busy school and they'll come out with the same tired old line about why do we have to have 24hr 20mph zones and the ranting and raving goes on. Motorists support school 20mph zones as it doesn't threaten their world view, just splash a 20 zone for 2x30 minute periods and it is business as usual. If you have 20mph zones in even a small percentage of roads it starts to affect people's bad habits - the monospeed drivers, the aggressive drivers and so on.


I still can't work out if this is a pro or anti-20mph limit stance.

Personally I live in a 30 limit, a narrowish cul-de-sac, but it's right off a 20 limit main road which is wide enough to get 3 cars side by side. Interestingly most of the 'accidents' used to justify the move to a 20 limit were on the side roads... it just doesn't make sense. I wouldn't have a major issue with the main road being 20 if the side roads were or if the main road was a 30 & the side roads 20


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## marinyork (12 Dec 2009)

GrasB said:


> I still can't work out if this is a pro or anti-20mph limit stance.
> 
> Personally I live in a 30 limit, a narrowish cul-de-sac, but it's right off a 20 limit main road which is wide enough to get 3 cars side by side. Interestingly most of the 'accidents' used to justify the move to a 20 limit were on the side roads... it just doesn't make sense. I wouldn't have a major issue with the main road being 20 if the side roads were or if the main road was a 30 & the side roads 20



It's not pro or anti anything. I've long advocated that the default speed limit in residential areas should be 25mph and that on single carriageway roads national be 50mph with the added ability to make a few 60mph and so on. At various points in time that's been more radical on what is on offer/less radical depending on who you ask/time period.

If pretty much everything was made 20, which is the direction things are going it would not be my first choice policy but I would go along with it. There are several variants of 20 zones knocking around but several councils have got a lot more serious about the idea the last 2 or 3 years.


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## thomas (13 Dec 2009)

marinyork said:


> If pretty much everything was made 20, which is the direction things are going it would not be my first choice policy but I would go along with it. *There are several variants of 20 zones knocking* around but several councils have got a lot more serious about the idea the last 2 or 3 years.




There are a couple near me. Along some side streets, where you'd be a crazed lunatic to actually do 20 or more....and along a stretch along unthank where there are lots of shops and peds. Most people seem to be doing around 20 mph there as I can draft them all . Again, I wouldn't want to drive along there at more than 20mph really.

I'm kinda for 20mph. I think at times they are a good idea, but I think if I started driving regularly again they could annoy me. I'm against turning national speed limit to 50 though. If a road should be 50, then stick some signs up...otherwise leave it alone.


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## thomas (26 Dec 2009)

http://www.dailymail.co.uk/news/art...d-limit-zones-reduced-road-casualties-20.html



> Roads where a 20mph limit was introduced suffered 41.9 per cent fewer casualties and collisions than faster roads -equivalent to 203 fewer injuries a year.


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## benborp (26 Dec 2009)

thomas said:


> http://www.dailymail.co.uk/news/art...d-limit-zones-reduced-road-casualties-20.html



So where did the Mail get their headline from?


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## dellzeqq (27 Dec 2009)

that's the genius of sub-editing!


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