Speed limits?

[StuartG]

Like you, I'm not sure about the 85 percentile research but intuitively it feels right.

I would refer the learned gentleman to my earlier post on Safespeed:

Yes, yet another outstanding example of a graduate from the Dr Andrew Wakefield School of Statistical Inference.

If you can't see the illogicalities in the proposition for yourself than forgive me it will be pointless to waste further time ... just as pointing out simple facts to the JABS people was a waste of time. Meanwhile needless lives were lost & damaged.

You do appear here as a troll.

 

[JamesMorgan]

I would refer the learned gentleman to my earlier post on Safespeed:

Yes, yet another outstanding example of a graduate from the Dr Andrew Wakefield School of Statistical Inference.

If you can't see the illogicalities in the proposition for yourself than forgive me it will be pointless to waste further time ... just as pointing out simple facts to the JABS people was a waste of time. Meanwhile needless lives were lost & damaged.

You do appear here as a troll.

I'm sorry, but I can't see how drawing a comparison between accidents caused by traffic moving at different flow speeds and some discredited research on vaccines has any relevence. If you have some research that counters my inituitive view that travelling at a similar speed to the rest of the traffic flow is safe then I welcome it.

By the way, a 'troll' is normally someone who posts outrageous comments in order to bait people for an answer. They will typically use insults and are rarely interested in providing any real discussion around the main topic area. I think your response is a classic example.

 

[StuartG]

By the way, a 'troll' is normally someone who posts outrageous comments in order to bait people for an answer. They will typically use insults and are rarely interested in providing any real discussion around the main topic area. I think your response is a classic example.

My dear friend - look back - I think you will find my comment was one of the rather more restrained responses.

If you want a serious discussion then you need a serious proposition. The arguement that travelling at 85% is the safest within a peloton of traffic is clearly independent of the safest average (or maximum) speed for that peloton. There is also the obvious illogicality that if you restrict people travelling faster than the 85 percentile - then you shift the percentiles down until you are all stationary.

The safest speed is a little more difficult to determine than the simpleton argument propounded by Safespeed. Is that insult or fact?

 

[JamesMorgan]

My dear friend - look back - I think you will find my comment was one of the rather more restrained responses.

If you want a serious discussion then you need a serious proposition. The arguement that travelling at 85% is the safest within a peloton of traffic is clearly independent of the safest average (or maximum) speed for that peloton. There is also the obvious illogicality that if you restrict people travelling faster than the 85 percentile - then you shift the percentiles down until you are all stationary.

The safest speed is a little more difficult to determine than the simpleton argument propounded by Safespeed. Is that insult or fact?

I think you will find that these were all points previously made by me, so I am somewhat confused as we appear to be in agreement. My argument was that in order to achieve a safe driving speed at 20mph we first need to enforce a speed limit of 20mph. I don't support restricting driving faster than the 85th percentile - as you say it is mathematically unachievable anyway. You seem to feel that I am in some way supportive of the Safespeed website, when my messages seem to indicate the contrary. I have just happened to use some of the research on their website about accident rates and speed differentials. Whatever we think about Safespeed there does appear to be quite a lot of evidence that speed differentials are a major cause of accidents (as is inapproriate speed).

 

[JamesMorgan]

In my experience (and I have a history with safespeeding) it's very dangerous to take any notice of their "evidence".

Unless you think that, for example, sitting in your car in a garage with a stopwatch and looking out of a window to determine the distractive effects of a speedometer is credible evidence. That was one of the most outlandish examples, but even his interpretation of other people's proper figures is worthless.

I suspect you are right - esp. in the way that their conclusions are drawn from various items of research. However, regarding the 85th percentile there does appear to be quite a broad amount of evidence around accident rates. What I hadn't realised until I just googled it, is that many countries (including the UK and US) do currently set speed limits based on the 85th percentile. This does appear to lead to the slighty crazy approach that you can't set a lower speed limit than the 85th percentile. You first have to lower speed (through measures such as road calming), then once the 85th percentile has fallen you can lower the speed limit. I don't think this applies in 30/20 mph zones though.

 

[StuartG]

The whole fallacy of the Safespeed idea is that because there is an inherent danger in speed differentials then we should let motorists manage the speed and keep up with an unlimited pack. This is ludicrous nonsense. They then falsely (and from reading the rest of the site I suspect knowingly) translate danger into safety policy.

Within it own deranged world it is rubbish. It equates a crash at 20mph with one at 80mph. Whether passenger, cyclist or pedestrian - those pose very, very different risks/outcomes.

The site is one (and this is why I mentioned JABS) that take an idea which may or may not be true in itself and with an agenda not based on evidence seek to extend it well outside its limitations to befuddle, confuse and get their agenda promoted while ignoring or even discrediting all the hard and non-controversial evidence to the contrary.

This really annoys me. And why I, amongst others here, will shout baloney when we see it. And have our suspicions about those that continue to give it credence.

 

[JamesMorgan]

The whole fallacy of the Safespeed idea is that because there is an inherent danger in speed differentials then we should let motorists manage the speed and keep up with an unlimited pack. This is ludicrous nonsense. They then falsely (and from reading the rest of the site I suspect knowingly) translate danger into safety policy.

Within it own deranged world it is rubbish. It equates a crash at 20mph with one at 80mph. Whether passenger, cyclist or pedestrian - those pose very, very different risks/outcomes.

The site is one (and this is why I mentioned JABS) that take an idea which may or may not be true in itself and with an agenda not based on evidence seek to extend it well outside its limitations to befuddle, confuse and get their agenda promoted while ignoring or even discrediting all the hard and non-controversial evidence to the contrary.

This really annoys me. And why I, amongst others here, will shout baloney when we see it. And have our suspicions about those that continue to give it credence.

OK - I now know where you are coming from, and am broadly in agreement.

 

[StuartG]

OK - I now know where you are coming from

Keep checkin' those mirrors dude

 

[wafflycat]

My take on speed is that you must be in control of your vehicle and be able to stop in the distance you can see to be safe. Not as easy as you think and painfully slow in many circumstances. Try it the next time you are out driving, you will be surprised,

Well no, I wouldn't be surprised. Not because I'm a brilliant driver but because it's a *basic* motoring skill of the sort those of us who have a full driving licence had to demonstrate competency in in order to pass the test to gain that full licence.

I'm constantly shocked, by those of us who have full licences, at the excuses made for poor driving when it's *basic* skills not being talked about. What is it amongst too many of us driving that once we've passed the test and got the full licence that means basic skills go out of the window or are deemed somehow difficult to do? It's as if once passed the test basic skills, competencies and rules no longer apply or are suddenly too difficult to do.