Balanced story on 20mph limits

[SquareDaff]

Nice way to rewrite history. You said statistics are not evidence. That is bull. It's obvious you can't take evidence from one situation and apply it to another, different situation, and I never said you could.

I also never said that all speed bumps everywhere save lives. What definitely does save lives is significantly lowering the speed of traffic, no matter how you go about achieving that.

I think we should agree to disagree. I will continue to base my conclusions on the 20mph zones on my daily experiences (not anecdotes!) and you can base yours on whatever metrics you deem valid. I will obviously never convince you that 20mph zones don't work in my area (my original point) and you will never convince me otherwise!!

 

[benb]

I think we should agree to disagree. I will continue to base my conclusions on the 20mph zones on my daily experiences (not anecdotes!) and you can base yours on whatever metrics you deem valid. I will obviously never convince you that 20mph zones don't work in my area (my original point) and you will never convince me otherwise!!

Not at all, I have no idea whether they work in your area. I was simply explaining that your day to day experiences (btw what do you think anecdotes are, if not personal experiences?) aren't necessarily representative of the whole situation or position, and proper studies with large amounts of data are the only reliable way of measuring this sort of thing.

 

[SquareDaff]

Not at all, I have no idea whether they work in your area. I was simply explaining that your day to day experiences (btw what do you think anecdotes are, if not personal experiences?) aren't necessarily representative of the whole situation or position, and proper studies with large amounts of data are the only reliable way of measuring this sort of thing.

Rot. It was "daily 1st hand experience" that led most people to conclude that the sun went round the earth.
Appearances can be deceptive, and our intuition is often wrong.

Take the 's' off and you'll be close - but anecdotes also don't necessarily have a basis in fact as they're prone to exaggerations. And then we could get into the "I ride this route every day" and "statistics say this" arguement again.

Have included your first comment to me on this little verbal merry go round. I'd hardly call that response "explaining" unless all your explanations start with the word "Rot". You've had your chance to convert me and failed and visa versa with me. Let's let other people have their chance to express their opinions now shall we?

 

[MacB]

I think we should agree to disagree. I will continue to base my conclusions on the 20mph zones on my daily experiences (not anecdotes!) and you can base yours on whatever metrics you deem valid. I will obviously never convince you that 20mph zones don't work in my area (my original point) and you will never convince me otherwise!!

Which is fair enough, but, from my reading of it you're stating they don't work due to poor implementation rather than they can't work, in your area.

I also noted your comments around 'rat runs', it does make me chuckle, mainly because I'm in a cul-de-sac so no chance of it happening here. Yes people will do it whenever possible, yet the same people would complain bitterly if the same was done where they lived. I've known, and been driven by, people that take a huge amount of pride in using convoluted time saving routes. Whether they actually save time can be up for debate, certainly in some instances. But, to a man, and they have all been men, they drive in the same style. Agressive, lots of accelerating and heavy braking, with little tolerance for the slightest perceived delay. It may be that the very type of driver likely to 'rat run' increases the danger. Coincidentally they've all been people that take pride in living somewhere quiet and relatively traffic free.

 

[SquareDaff]

Which is fair enough, but, from my reading of it you're stating they don't work due to poor implementation rather than they can't work, in your area.

Thanks for the constructive reply. Yes - where I am they simply don't work because the main method used to slow traffic is speed humps which can be straddled by any reasonably sized car. I think I mentioned that if they want to slow traffic down then putting the raised strip all the way across the road would be much more effective.

I can see the arguement that slowing traffic down will reduce the risk of injury/fatalities - but it isn't the only thing that will achieve this and not all the methods used to do this will succeed. My wife was involved in a car accident where a teenager stepped right out in front of her without looking. Fortunately for her, and him, she was only doing 15-20mph and he escaped with a few bruises after kissing the windscreen! It took her ages before she could get back behind a wheel again despite there being nothing she could have done. Anyway...I digress. Reduce speed using effective measures that won't put other road uses (i.e. me on my bike) in danger but also educate pedestrians in tandem. If they both reduce casualties by 10% why restrict yourself to one measure!! (sorry getting carried away again!! )

I also noted your comments around 'rat runs', it does make me chuckle, mainly because I'm in a cul-de-sac so no chance of it happening here.

The same here....but I notice it happening on the roads to the relative safety of my cul-de-sac!

Yes people will do it whenever possible, yet the same people would complain bitterly if the same was done where they lived. I've known, and been driven by, people that take a huge amount of pride in using convoluted time saving routes. Whether they actually save time can be up for debate, certainly in some instances. But, to a man, and they have all been men, they drive in the same style. Agressive, lots of accelerating and heavy braking, with little tolerance for the slightest perceived delay. It may be that the very type of driver likely to 'rat run' increases the danger. Coincidentally they've all been people that take pride in living somewhere quiet and relatively traffic free.

Agree with all of this entirely.

Just re-read this. Think I'm trying to say...if saving lives is really your aim then don't try and do it on the cheap. Use Education (long term benefit) and restriction (short term benefit).

 

[Chutzpah]

This thread has continually made the following phrase pop into my mind... "the plural of anecdote is not data"

 

[StuartG]

So squaredaft - where is your evidence (not intuition) that your own 20 mph zone doesn't work together with a control which is statistically significant?

The London report was careful to try and test the results against the nearest possible control (the areas adjoining the zones) and spelled out the limitations of the trial. But AFAIK nobody has challenged the analysis and I guess a good few petrolheads have tried and failed.

So a reasonable person would see the best evidence points to 20mph zones in London work although we are still a little unclear why but would want to see the success replicated wherever possible. Or do we have a different view of what constitutes a reasonable person?

 

[davefb]

well, i wish they'd extend the 20mph zone near me, onto my road.. its insane the speed people go.

as for the rubbish about 'speeds' and not causing accidents..

thats not the point is it.. the point is that you get less injuries at lower speeds. how some people seem unable to grasp that concept beggers belief..

i think what has happened over my lifetime, is that with the attitude of 'speed limits' and them being evil, is that a lot more drivers seem to drive at the limit not at 'what would be a sensible speed', could be that cars are a lot quieter now with better grip/power etc... either that or peoples iq's have dropped substantially to the point that they think steaming down a road with parked cars either side, only one lane wide at 30+mph is a sensible thing..

 

[ufkacbln]

I don't instinctively know any answer. It's called daily 1st hand experience. No report will ever beat that for arriving at conclusions!


I completely agree with this! My arguement goes further. Sticking speed humps in the middle of the road doesn't a 20mph zone make either. Drivers just straddle them at their original speed making it more dangerous for cyclists (for example) as we have to move to the left to get round them - and motorists have to do the same to straddle them! If you're going to use speed restraints they have to be the ones that cover the full width of the road and not the cheapo humps!!

Near us is a School that is wonderful to watch the drivers doing exactly this, apart from two that are completely across the road, and are the only two that work!

Slows drivers far more effectively than the split ones.

.. and as an aside, anyone remember the "speed calming kills thousands of people per year by slowing ambulances" farce?

 

[ufkacbln]

This thread has continually made the following phrase pop into my mind... "the plural of anecdote is not data"

.. and apparently personal experiences aren't anecdotes either!

However in some cases like his the use of anecdotal and personal data is entirely relevant, to ascertain the "soft" effects that should be influencing the decision making process.

"I now allow my children to walk down to the shop as I feel the road is safer" is an entirely valid piece of 'evidence' in the context of assessing the effect of a 20 mph limit.

 

[Jaguar]

Really can't see what Paul Watters of the AA is bleating about

Is that the same AA chap who was complaining about the recent drop in driven miles? something like "driving less is going to further ruin the economy. This country needs people to buy more petrol and drive the economy into recovery. People who don't drive aren't buying goods and services .... blah blah"

Because cyclists don't need to buy food, or Starbucks, or "stuff"

 

[ufkacbln]

Is that the same AA chap who was complaining about the recent drop in driven miles? something like "driving less is going to further ruin the economy. This country needs people to buy more petrol and drive the economy into recovery. People who don't drive aren't buying goods and services .... blah blah"

Because cyclists don't need to buy food, or Starbucks, or "stuff"

Can't find the quote - so can't authenticate this, but....

I remember some years ago there was a discussion which came to the conclusion that a cyclist passing through an area is beneficial as they spend more than motorists in local shops and do less environmental damage.