RE: 30mph safer than 20mph: campaign
Thursday 21st December 2006
Could be safer than 20mph?Safe Speed has today criticised the Department for Transport and the Scottish Executive for failing to consider figures that show 20mph speed limit zones have crashes which it said are, on average, more dangerous than those in 30mph zones.
30mph safer than 20mph: campaign
Stats prove slower is not always safer
Could be safer than 20mph?
According to Safe Speed, official figures show that the likelihood of a casualty being fatally or seriously injured in 2005 was:
- 11.85 per cent in 20mph zones
- 10.26 per cent in 30mph zones
According to Safe Speed, there's a range of possible explanations including:
- A greater proportion of 20mph zone crashes include vulnerable road users
- 20mph zones are created in places where dangers are greatest
- 20mph zones create an illusion of safety, where people take less care
- Some drivers in 20mph zones are so busy attempting to maintain 20mph that they simply don't brake before impact, possibly because they are looking at their speedos when something goes wrong.
- 20mph zones encourage drivers to actually travel at 20mph when 10 or 15mph may have been a better choice.
Campaign founder Paul Smith said: "It isn't safe to continue to roll out 20mph zones willy-nilly until we have a proper understanding of the higher average crash severity that they are associated with. As is common with modern road safety interventions this has not been investigated - they do it because they believe it should work.
"At first 20mph had to be 'self enforcing' with traffic calming measures used to create an environment in which 20mph seemed like a natural speed. But since then there has been 'mission creep' and 20mph zones are being installed widely without such features.
"If drug companies behaved like this there would be a national outcry, but with road safety everyone has an opinion. Far too often they claim that 'it's obvious' that a given intervention should work. This cavalier attitude has taken us from being the fastest improving country in Europe to the slowest (in the EU15). Like drugs, road safety interventions come with side effects and unintended consequences.
"The authorities continue to treat road safety as a problem of vehicle physics when in fact it is a complex problem of human psychology. It's all very well citing examples of 'model' schemes, but with serious anomalies appearing, the need for properly conducted randomised trials has never been clearer.
"There's no indication that any of the 'speed kills' policies have made our roads safer. Speed cameras, traffic calming, speed limit reductions and so on have all been rolled out across the country with no significant reduction in road deaths or road crash hospitalisations."
Discussion
Lord-Flasheart said:
Yea but on a narrow residential street where children might be playing there is a greater chance they will live if you hit them at 20 as opposed to 30
There's an even greater chance they'll survive if your observational skills are up to scratch and you avoid them altogether.This says that, in the event of a crash, it is slightly more likely to result in a KSI if it's in a 20 zone than in a 30.
However, it does not address whether the crash itself is more likely in a 20 or a 30.
With such a tiny difference between the KSI likelihoods, the likelihood of a crash in the first place is probably much more important.
I'm not saying that 20s are safer, but in this particular release Paul's statistics are far from being definitive.
BliarOut said:
Lord-Flasheart said:
Yea but on a narrow residential street where children might be playing there is a greater chance they will live if you hit them at 20 as opposed to 30
There's an even greater chance they'll survive if your observational skills are up to scratch and you avoid them altogether.Not a lot you can do though if someone dives out from behind a van or a car. All you can do is your best to avoid them and at 20mph that will be a lot easier than 30mph.
danrc said:
All you can do is your best to avoid them and at 20mph that will be a lot easier than 30mph.
The difference of 10mph might have an effect on sustained damage. Even of reaction times. I however would not say "A LOT EASIER". The margins will be very low. My main concern with the argument of children playing on roads is simple. It's not a playground. Never was and should never be considerd a playground. Kids must be educated in road safty. They must also be given a safe place to play away from cars and a sensible way of getting there. i.e. a crossing if there's a main road. It's a complex issue but hazzard awareness needs improving on drivers and padestrians. I firmly believe that this will make a hugh difference to accidents and not a 10mph drop in speed. This as mentioned before gives a false impression that been hit at 20mph won't hurt! Even 5mpg will hurt if it's a bus. danrc said:
BliarOut said:
Lord-Flasheart said:
Yea but on a narrow residential street where children might be playing there is a greater chance they will live if you hit them at 20 as opposed to 30
There's an even greater chance they'll survive if your observational skills are up to scratch and you avoid them altogether.Not a lot you can do though if someone dives out from behind a van or a car. All you can do is your best to avoid them and at 20mph that will be a lot easier than 30mph.
flemke said:
This says that, in the event of a crash, it is slightly more likely to result in a KSI if it's in a 20 zone than in a 30.
However, it does not address whether the crash itself is more likely in a 20 or a 30.
With such a tiny difference between the KSI likelihoods, the likelihood of a crash in the first place is probably much more important.
I'm not saying that 20s are safer, but in this particular release Paul's statistics are far from being definitive.
I don't think Paul's trying to be definitive here. I think he's just saying that there's an anomaly that needs investigation. It's easy to explain away the fact that -- at the very least -- there's no improvement in outcome in 20 over 30 limits and ascribe it to there being more children/higher risk, but it would be more sensible to investigate it.
I think the issue with road safety is that there's never a downside to lower limits from the perspective of the enforcers. They think that any limit is worth reducing if there's any benefit at all, because nobody suffers if the benefit isn't there. In fact, lower limits increase journey times, increase frustration, and may increase risk. The value of these factors seems to be routinely ignored.
As Paul implies, if this was a drug trial, the fact that 20 limits did not improve the outcome over 30 limits would be used by NICE to say that the investment in 20 limits (because they cost more, see above) over 30 limits was not justified. As it's road safety, the downsides of 20 limits are ignored. There is far too much arm-waving and far too little science applied to road safety.
danrc said:
BliarOut said:
Lord-Flasheart said:
Yea but on a narrow residential street where children might be playing there is a greater chance they will live if you hit them at 20 as opposed to 30
There's an even greater chance they'll survive if your observational skills are up to scratch and you avoid them altogether.Not a lot you can do though if someone dives out from behind a van or a car. All you can do is your best to avoid them and at 20mph that will be a lot easier than 30mph.
Conversely, the car doing 30mph wouldn't hit them at all as it would have passed the scene already.
And if somebody dives out from behind a car, thats nobody's fault but somebody's.
Edited by Parrot of Doom on Thursday 21st December 12:14
The argument, what happens if someone leaps out in front of you seems a little spurious. When I'm driving I take responsibility for my own safety, when I'm walking I do the same. If I can't see whether there's a car coming I stay on the pavement. It's a very simple road using technique...... don't step into the path of moving vehicles!
To put the argument the other way, should pedestrians be banned from running on the pavement as they will have less time to avoid a car if it mounts the pavement or pulls in a drive? The argument is identical yet if I swung into a driveway and flattened someone on the pavement it would (quite rightly) be my fault.
To put the argument the other way, should pedestrians be banned from running on the pavement as they will have less time to avoid a car if it mounts the pavement or pulls in a drive? The argument is identical yet if I swung into a driveway and flattened someone on the pavement it would (quite rightly) be my fault.
Edited by MilnerR on Thursday 21st December 12:36
Lord-Flasheart said:
Yea but on a narrow residential street where children might be playing there is a greater chance they will live if you hit them at 20 as opposed to 30
But if it is a narrow residential street where the limit is 30, you may limit yourself to 25 and keep looking at the road, comfortable that you are under the speed limit. If the limit is 20, then you may be constantly monitoring your speedo rather than looking where you are going and thus maybe more likely to hit a child.
I think it is this that Paul is trying to point out.
If you only had the 2 choices would you rather have a 20 limit with a 10% chance of their being an accident in a year or a 30 limit with a 5% chance.
I think there was also a point made that in 20 limits peole were getting hit a 20 because the driver wasn't looking. In a 30 limit, the impact speed may be down to 20 anyway if the drivers hits the brakes before impact.
Its all speculation and that is the problem. Nobody has yet proved that a 20 limit is safer than a 30.
For 20mph to work the "context" of the road must promote this, via traffic calming (NOT speed bumps etc). If road makes you only want to travel at 20, then you will not need to continually look at the speedo. If however the road is a fast road with a very low limit then the benfits will be negated.
I think everyone is being a little naive. I mean if a child were to run out after a ball for instance and you were to hit them at 20, they would stand a far better chance if survival at this speed than if you were to hit them at 30.
I know everyone has their own responsability but accidents happen (especially where children are involved) and if the death toll can be reduced then so much the better.
On another point, it doesn't take to much to watch your speed at 20, or 30 or any other speed for that matter. You don't have to sit watching yor speedo every other second to make sure you don't creep over the limit by 1mph.
I know everyone has their own responsability but accidents happen (especially where children are involved) and if the death toll can be reduced then so much the better.
On another point, it doesn't take to much to watch your speed at 20, or 30 or any other speed for that matter. You don't have to sit watching yor speedo every other second to make sure you don't creep over the limit by 1mph.
It's naive to think simplisticly - that 20mph is safer than any higher speed just because someone might run out in front of you. Anyone who thinks this needs to study Safespeed's research while opening their mind to the great number of considerations - driver concentration (which is usually better at higher speeds), driver mood (which is usually better when not constattly confronted with very low speed limits, humps, chacanes and so on), parental control of children, etc etc. "20 is better than 30" is neanderthal thinking...think deeper.
I think it boils down yet again to a Government quick to legislate and blame in black and white terms...
There are prevailing conditions when to do 30 in a 30 limit is lethal, others when on the same stretch, it is acceptable. The key point is the use of appropriate speed. This can only be based on case by case basis. When I was younger and more reckless, traffic plod seemed to be everywhere...usually when I was doing something really dumb! A rollocking by the bib usually hit the mark and did make me change my ways.
I do agree with the earlier point, a road is a DANGEROUS place and no amount of speed cameras, traffic calming or reducing speed limits is going to change that. In the past, inspired individuals with a green cross motif, would educate little people not to run on the pavements, to cross the road safely...something sadly missed by the PM who claims his top three targets as education, education and education...
I do think there are things that could be done to improve safety and lower the death rates, shifting school times out of rush hour, US style compulsory school bus schemes, closing roads outside schools during school hours or 5 mph speed limits (with as many scameras as they want) to enforce with zero tolerance WHEN THERE ARE KIDS AROUND... All of which would inconvenience the motorist to some extent but I doubt many would complain too loudly as an obvious link would exist between the action and safety.
I could rant on about congestion etc and the proposed increase taxation of the workers of the country...sorry, congestion reducing road charging...when simple things have not been tried, eg tax breaks for work from home or flexi-time, penalise mid lane hogs on the motorways (surely a camera could be made to catch this!)...
There are prevailing conditions when to do 30 in a 30 limit is lethal, others when on the same stretch, it is acceptable. The key point is the use of appropriate speed. This can only be based on case by case basis. When I was younger and more reckless, traffic plod seemed to be everywhere...usually when I was doing something really dumb! A rollocking by the bib usually hit the mark and did make me change my ways.
I do agree with the earlier point, a road is a DANGEROUS place and no amount of speed cameras, traffic calming or reducing speed limits is going to change that. In the past, inspired individuals with a green cross motif, would educate little people not to run on the pavements, to cross the road safely...something sadly missed by the PM who claims his top three targets as education, education and education...
I do think there are things that could be done to improve safety and lower the death rates, shifting school times out of rush hour, US style compulsory school bus schemes, closing roads outside schools during school hours or 5 mph speed limits (with as many scameras as they want) to enforce with zero tolerance WHEN THERE ARE KIDS AROUND... All of which would inconvenience the motorist to some extent but I doubt many would complain too loudly as an obvious link would exist between the action and safety.
I could rant on about congestion etc and the proposed increase taxation of the workers of the country...sorry, congestion reducing road charging...when simple things have not been tried, eg tax breaks for work from home or flexi-time, penalise mid lane hogs on the motorways (surely a camera could be made to catch this!)...
danrc said:
I think everyone is being a little naive. I mean if a child were to run out after a ball for instance and you were to hit them at 20, they would stand a far better chance if survival at this speed than if you were to hit them at 30.
I know everyone has their own responsability but accidents happen (especially where children are involved) and if the death toll can be reduced then so much the better.
On another point, it doesn't take to much to watch your speed at 20, or 30 or any other speed for that matter. You don't have to sit watching yor speedo every other second to make sure you don't creep over the limit by 1mph.
I know everyone has their own responsability but accidents happen (especially where children are involved) and if the death toll can be reduced then so much the better.
On another point, it doesn't take to much to watch your speed at 20, or 30 or any other speed for that matter. You don't have to sit watching yor speedo every other second to make sure you don't creep over the limit by 1mph.
You're missing the point though - it's about selecting an appropriate speed to allow you to anticipate potential hazards within the distance you can see in front and around you. This appropriate speed varies all the time. Whilst there may be an issue with some drivers who stick to 30 in 30 limits when they shouldn't, cutting the speed limit to 20 on residential roads just exascperates the problem of drivers who drive at the speed limits all the time and also encourages ALL drivers to drive by numbers even more.
I'd be very interested to know (I wonder if Paul knows) how many accidents there are each year involving children being hit at over 20? And then out of that, how many actually involve the driver going too fast for the conditions as opposed to children just playing chicken on busy roads?
All this is beside the point. I don't think I've ever seen a car doing 20 in a 20 before. Have you? Plus if you were to do 20 you would probably fall asleep at the wheel and mow down a large gathering of children standing on the pavement. 20 is ridiculous! its not even on the Speedo of many cars and if it is then its probably not accurate!
If I see a hazard such as a child who may cross the road, parked cars or a narrow area which may require me to go slowly I slow down accordingly. Those who don't are never going to slow down to 20 because of some signs or speed humps anyway because they are obviously bad drivers and not aware that their actions are dangerous. A sign won’t change this, training might.
If I see a hazard such as a child who may cross the road, parked cars or a narrow area which may require me to go slowly I slow down accordingly. Those who don't are never going to slow down to 20 because of some signs or speed humps anyway because they are obviously bad drivers and not aware that their actions are dangerous. A sign won’t change this, training might.
i think the figures above are a bit useless unless you know the reasons behind why the accidents happened. you might find that all the accidents in the 20mph zone were caused by drivers doing 30mph.
in the figures above there are no figures given in how many incindents were looked at to arrive at those results, and i think if a safety camera partnership put out such vague figures, then paul would be all over them.
in the figures above there are no figures given in how many incindents were looked at to arrive at those results, and i think if a safety camera partnership put out such vague figures, then paul would be all over them.
eccles said:
i think the figures above are a bit useless unless you know the reasons behind why the accidents happened. you might find that all the accidents in the 20mph zone were caused by drivers doing 30mph.
in the figures above there are no figures given in how many incindents were looked at to arrive at those results, and i think if a safety camera partnership put out such vague figures, then paul would be all over them.
in the figures above there are no figures given in how many incindents were looked at to arrive at those results, and i think if a safety camera partnership put out such vague figures, then paul would be all over them.
I thought that was the whole point of the artice, ie the lack of knowledge. We keep introducing 20 limits but they appear to be more dangerous than 30s, the questions are why, and should we continue to introduce them whilst we don't know?
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