Cutting speed limits for cleaner air?
Discussion
Evanivitch said:
jmorgan said:
Seemed to get worse when they re arranged the traffic flow around the two bridges.
I'll admit I was a sceptic but I genuinely like the new bridge layoutAll this work and money spent, yet town is still gridlocked most days. I tend to go to Llanelli now as it's far easier to get to the shops!
eccles said:
I was born and grew up in Swansea but moved away many years ago, but I still visit family regularly. I find the road layout changes over the last 20 years or so to be quite bewildering. It seem every time I come home the layout has changed and even a friend who is a taxi driver says it's frustrating.
All this work and money spent, yet town is still gridlocked most days. I tend to go to Llanelli now as it's far easier to get to the shops!
Swansea will always suffer because access from the South and immediately west (Gower) is limited. But personally I think the improvements have been significant.All this work and money spent, yet town is still gridlocked most days. I tend to go to Llanelli now as it's far easier to get to the shops!
Evanivitch said:
eccles said:
I was born and grew up in Swansea but moved away many years ago, but I still visit family regularly. I find the road layout changes over the last 20 years or so to be quite bewildering. It seem every time I come home the layout has changed and even a friend who is a taxi driver says it's frustrating.
All this work and money spent, yet town is still gridlocked most days. I tend to go to Llanelli now as it's far easier to get to the shops!
Swansea will always suffer because access from the South and immediately west (Gower) is limited. But personally I think the improvements have been significant.All this work and money spent, yet town is still gridlocked most days. I tend to go to Llanelli now as it's far easier to get to the shops!
There's another shove for these type of measures from Kings College ERG in the news today. It's making headlines and why not, who doesn't want better air quality?
Apparently 50 million years of human life "could" be saved by reducing NOx and particulates through to 2154.
Getting hold of a copy of the paper from The Lancet Planetary Health journal is a work in progress. It'll be interesting to see how the average 10x worse levels of indoor air pollution (compared to outdoor urban air) have been taken into account, and how far the difference between emissions and levels is preserved when taking about ~60% reductions (i.e. in what, traffic emissions or atmospheric levels).
So far media coverage has trotted out the expected epidemiological fallacy with the 40,000 annual deaths number. As always this media coverage doesn't explain how premature deaths and lost life / life-years time totals are based on estimates of life expectancy compared to what actually happened, nor how the people bulked in the study are almost all indoors not outdoors and that no measurements were taken of the air pollution levels each person represented was exposed to.
For an indication of the less-than-obvious issues in play, anyone coming to this fresh could do worse than read about exactly how such studies are flawed (the author at the link below is a capable statistician so at least it's not armwaving):
http://wmbriggs.com/post/13029/
Also, consider asthma - a most unpleasant and very dangerous / potentially fatal condition which health services will rightly continue to address with whatever resources are allocated. The situation with asthma and air quality, including NOx and particulates, was examined nearly 20 years ago in a 1999 report for the NHS executive entitled 'Transport and Health in London' which concluded (section C5 p44): "the available evidence does not support a causative role for outdoor air pollution".
This conclusion was inescapable when asthma incidence had risen overall for the preceding 25 years while NOx and particulates and other pollutants had fallen significantly over the same period. Percentages greater than 100 arise when individual % falls for pollutants are summed.
Even better air quality is a good thing but great care is still needed when faced with media reports about the impact of 'air quality' (outdoors) when air quality indoors is much worse on average with the two lumped together using bulk data with no individual exposure levels in sight - yet conclusions relate to only one (outdoors).
Apparently 50 million years of human life "could" be saved by reducing NOx and particulates through to 2154.
Getting hold of a copy of the paper from The Lancet Planetary Health journal is a work in progress. It'll be interesting to see how the average 10x worse levels of indoor air pollution (compared to outdoor urban air) have been taken into account, and how far the difference between emissions and levels is preserved when taking about ~60% reductions (i.e. in what, traffic emissions or atmospheric levels).
So far media coverage has trotted out the expected epidemiological fallacy with the 40,000 annual deaths number. As always this media coverage doesn't explain how premature deaths and lost life / life-years time totals are based on estimates of life expectancy compared to what actually happened, nor how the people bulked in the study are almost all indoors not outdoors and that no measurements were taken of the air pollution levels each person represented was exposed to.
For an indication of the less-than-obvious issues in play, anyone coming to this fresh could do worse than read about exactly how such studies are flawed (the author at the link below is a capable statistician so at least it's not armwaving):
http://wmbriggs.com/post/13029/
Also, consider asthma - a most unpleasant and very dangerous / potentially fatal condition which health services will rightly continue to address with whatever resources are allocated. The situation with asthma and air quality, including NOx and particulates, was examined nearly 20 years ago in a 1999 report for the NHS executive entitled 'Transport and Health in London' which concluded (section C5 p44): "the available evidence does not support a causative role for outdoor air pollution".
This conclusion was inescapable when asthma incidence had risen overall for the preceding 25 years while NOx and particulates and other pollutants had fallen significantly over the same period. Percentages greater than 100 arise when individual % falls for pollutants are summed.
Even better air quality is a good thing but great care is still needed when faced with media reports about the impact of 'air quality' (outdoors) when air quality indoors is much worse on average with the two lumped together using bulk data with no individual exposure levels in sight - yet conclusions relate to only one (outdoors).
Relevant related info follows.
From 'Health Effects of Indoor Air Pollutants, Current Perceptions' by Dr Robert l Maynard.
"People in developed countries such as the United Kingdom (UK) spend more than 80% of their lives indoors; in less technologically developed countries the percentage of the day spent indoors is rather less than this. If we accept that the effects of exposure to air pollutants are in some way proportional to total exposure to those pollutants, it follows that the indoor environment may play a larger role than the outdoor environment."
"At least as far as daily deaths are concerned there is some evidence to suggest that the elderly and especially those suffering from chronic heart and lung disease are most likely to be affected. Now it is likely that such people spend more than an average amount of time indoors: they are certainly not jogging in the park. Thus, we can deduce that the time-series studies are telling us something about the effects of indoor exposure to air pollutants."
In other words, far more so that outdoor air pollution.
From the USA Environment Protection Agency.
"In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors."
"In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly and the chronically ill, especially those suffering from respiratory or cardiovascular disease."
https://www.epa.gov/indoor-air-quality-iaq/inside-...
EPA finding support those published by Dr Jeff Llewellyn from the UK Buildings Research Establishment regarding UK indoor air being on average 10x more polluted than outdoor urban air with 100x levels measured.
From 'Health Effects of Indoor Air Pollutants, Current Perceptions' by Dr Robert l Maynard.
"People in developed countries such as the United Kingdom (UK) spend more than 80% of their lives indoors; in less technologically developed countries the percentage of the day spent indoors is rather less than this. If we accept that the effects of exposure to air pollutants are in some way proportional to total exposure to those pollutants, it follows that the indoor environment may play a larger role than the outdoor environment."
"At least as far as daily deaths are concerned there is some evidence to suggest that the elderly and especially those suffering from chronic heart and lung disease are most likely to be affected. Now it is likely that such people spend more than an average amount of time indoors: they are certainly not jogging in the park. Thus, we can deduce that the time-series studies are telling us something about the effects of indoor exposure to air pollutants."
In other words, far more so that outdoor air pollution.
From the USA Environment Protection Agency.
"In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors."
"In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly and the chronically ill, especially those suffering from respiratory or cardiovascular disease."
https://www.epa.gov/indoor-air-quality-iaq/inside-...
EPA finding support those published by Dr Jeff Llewellyn from the UK Buildings Research Establishment regarding UK indoor air being on average 10x more polluted than outdoor urban air with 100x levels measured.
turbobloke said:
Relevant related info follows.
From 'Health Effects of Indoor Air Pollutants, Current Perceptions' by Dr Robert l Maynard.
"People in developed countries such as the United Kingdom (UK) spend more than 80% of their lives indoors; in less technologically developed countries the percentage of the day spent indoors is rather less than this. If we accept that the effects of exposure to air pollutants are in some way proportional to total exposure to those pollutants, it follows that the indoor environment may play a larger role than the outdoor environment."
"At least as far as daily deaths are concerned there is some evidence to suggest that the elderly and especially those suffering from chronic heart and lung disease are most likely to be affected. Now it is likely that such people spend more than an average amount of time indoors: they are certainly not jogging in the park. Thus, we can deduce that the time-series studies are telling us something about the effects of indoor exposure to air pollutants."
In other words, far more so that outdoor air pollution.
From the USA Environment Protection Agency.
"In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors."
"In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly and the chronically ill, especially those suffering from respiratory or cardiovascular disease."
https://www.epa.gov/indoor-air-quality-iaq/inside-...
EPA finding support those published by Dr Jeff Llewellyn from the UK Buildings Research Establishment regarding UK indoor air being on average 10x more polluted than outdoor urban air with 100x levels measured.
Interesting points regarding indoor air pollution TBFrom 'Health Effects of Indoor Air Pollutants, Current Perceptions' by Dr Robert l Maynard.
"People in developed countries such as the United Kingdom (UK) spend more than 80% of their lives indoors; in less technologically developed countries the percentage of the day spent indoors is rather less than this. If we accept that the effects of exposure to air pollutants are in some way proportional to total exposure to those pollutants, it follows that the indoor environment may play a larger role than the outdoor environment."
"At least as far as daily deaths are concerned there is some evidence to suggest that the elderly and especially those suffering from chronic heart and lung disease are most likely to be affected. Now it is likely that such people spend more than an average amount of time indoors: they are certainly not jogging in the park. Thus, we can deduce that the time-series studies are telling us something about the effects of indoor exposure to air pollutants."
In other words, far more so that outdoor air pollution.
From the USA Environment Protection Agency.
"In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors."
"In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly and the chronically ill, especially those suffering from respiratory or cardiovascular disease."
https://www.epa.gov/indoor-air-quality-iaq/inside-...
EPA finding support those published by Dr Jeff Llewellyn from the UK Buildings Research Establishment regarding UK indoor air being on average 10x more polluted than outdoor urban air with 100x levels measured.
Is better ventilation the key to improving this or are there other factors?
Ventilation definitely helps, nothing more sophisticated than having a window open lets cleaner outdoor air in and allows more polluted indoor air to escape. Unfortunately using that approach means pollen can be a problem to lots of people at this time of year.
The heart of this situation is that the various people involved who allow the general public to mislead itself definitely know better but carry on anyway. There's no reason for Joe or Jo Public to look into this at the necessary level of detail, they think they can trust these people and will believe what they read/hear from them.
It's not too difficult to locate information showing how exceptionally weak the widely publicised claims are, but understandably there's little interest in doing so and little time in busy lives to do it even if there was some interest. Obviously, cleaner air everywhere would be a good thing but using the epidemiological fallacy to lay all the blame on outdoor air is way off the mark and clearly misleading.
It's far from clear that TPTB know what the relative proportions of NOx from greenery/transport/industry are, nor that the problem of trans-boundary particulate pollution (often from europe) is recognised as it should be.
The heart of this situation is that the various people involved who allow the general public to mislead itself definitely know better but carry on anyway. There's no reason for Joe or Jo Public to look into this at the necessary level of detail, they think they can trust these people and will believe what they read/hear from them.
It's not too difficult to locate information showing how exceptionally weak the widely publicised claims are, but understandably there's little interest in doing so and little time in busy lives to do it even if there was some interest. Obviously, cleaner air everywhere would be a good thing but using the epidemiological fallacy to lay all the blame on outdoor air is way off the mark and clearly misleading.
It's far from clear that TPTB know what the relative proportions of NOx from greenery/transport/industry are, nor that the problem of trans-boundary particulate pollution (often from europe) is recognised as it should be.
Ali G said:
Open a window?
How very dare you.
In today's triple glazed thermally efficient household, only HEPA filtration is appropriate.
Ooops How very dare you.
In today's triple glazed thermally efficient household, only HEPA filtration is appropriate.
HEPA will allow aldehydes, ketones, NOx and CO through, from sources such as cavity wall insulation and gas stoves/boilers, so we can be reassured that levels of pollutants in our kitchens and beyond will remain safely (!) above arbitrary outdoor air quality limits that would have the EU seeking hefty fines.
Transatlantic ecofolks in environmentally friendly California got a dose of reality a few years back when a Berkeley study analysed data from California homes to assess levels of indoor air pollution. It turned out that 60% of homes in the state that cook at least once a week with a gas stove reach pollutant levels that would be illegal if found outdoors...12 million Californians are routinely exposed to NOx levels above federal (outdoor) standards, 10 million are exposed to formaldehyde exceeding federal standards, and 1.7 million are exposed to carbon monoxide at naughty but non-fatal levels.
We're no different on this side of the pond but the focus is carefully held on far cleaner outdoor urban air as per this thread (no disrespect to the OP).
Nice shot from Kenfig nature reserve.
Port Talbot results were wrong. Actual values < 10.
https://www.walesonline.co.uk/news/wales-news/worl...
Port Talbot results were wrong. Actual values < 10.
https://www.walesonline.co.uk/news/wales-news/worl...
Evanivitch said:
Nice shot from Kenfig nature reserve.
Port Talbot results were wrong. Actual values < 10.
https://www.walesonline.co.uk/news/wales-news/worl...
who did the converting calculation of the estimates ,michael mann ? Port Talbot results were wrong. Actual values < 10.
https://www.walesonline.co.uk/news/wales-news/worl...
She said: “The PM2.5 level for the year 2015 for Port Talbot should be 9.6853 (and is rounded to 10 in the updated excel sheet) and is noted as ‘measured’.
“The PM2.5 was erroneously featured as a converted (estimated) value of 18.
I've been discussing this topic over email with a retired traffic engineer whom I know well, he's been out of the game for some time but is still interested in his former work and continues to read all info he can get his hands on including from former colleagues.
One of his recent messages offered a reminder that imposing lower speed limits on roads with high traffic volumes also imposes a significant economic burden.
£1bn per annum per 1mph reduction in average traffic speed is the lowest economic impact estimate he's seen, with other estimates up to 5x higher than that. He didn't quote a source but isn't prone to flights of fantasy. Feel free to disregard but with 'official' estimates of the direct and indirect costs of congestion to all UK motorists coming in at over £37bn (2017) imposing the same result as congestion i.e. lower speeds is bound to have a substantial economic downside.
Given that the lower speed limits idea is basically an exercise in avoiding extortionate EU fines it's hardly comforting to know that the 'solution' imposes a hefty cost all by itself.
One of his recent messages offered a reminder that imposing lower speed limits on roads with high traffic volumes also imposes a significant economic burden.
£1bn per annum per 1mph reduction in average traffic speed is the lowest economic impact estimate he's seen, with other estimates up to 5x higher than that. He didn't quote a source but isn't prone to flights of fantasy. Feel free to disregard but with 'official' estimates of the direct and indirect costs of congestion to all UK motorists coming in at over £37bn (2017) imposing the same result as congestion i.e. lower speeds is bound to have a substantial economic downside.
Given that the lower speed limits idea is basically an exercise in avoiding extortionate EU fines it's hardly comforting to know that the 'solution' imposes a hefty cost all by itself.
It's started on the M4... Went down there at 3am on Monday and the 50 signs were on the gantries. Heading east the fist gantry showing the limit is the one with the camera (what a coincidence, of course)
And what a waste of the expensive "variable" limit system!
Haven't been on the Port Talbot section yet but I'm assuming they will extend the average speed camera coverage as well.
Who in the Welsh government is worth contacting about this? Crap ideas like this make a mockery of the safety arguments and risk creating contempt even for justified limits, which might of course reduce safety
And what a waste of the expensive "variable" limit system!
Haven't been on the Port Talbot section yet but I'm assuming they will extend the average speed camera coverage as well.
Who in the Welsh government is worth contacting about this? Crap ideas like this make a mockery of the safety arguments and risk creating contempt even for justified limits, which might of course reduce safety
I'm at the point where if there is an alternative to the M1 I'll take it. Between Mansfield and Sheffield there are two four hour slots a day (IIRC) where it is perminantly a 60mph limit. Air quality is the reason, and monitored by yellow vultures.
It's nonsense. For one, at every camera there is a sea of braking. How is something which causes this action on a motorway safe? Secondly, this large scale braking then accelerating reduces MPG, negating the idea behind the reasoning. Thirdly, between cameras traffic finds it's natural speed anyway, often about 80mph. No one's paying any attention to the silly limits, is everybody doing it wrong?
If I met the person who thought of these schemes I would happily smack them in the face.
It's nonsense. For one, at every camera there is a sea of braking. How is something which causes this action on a motorway safe? Secondly, this large scale braking then accelerating reduces MPG, negating the idea behind the reasoning. Thirdly, between cameras traffic finds it's natural speed anyway, often about 80mph. No one's paying any attention to the silly limits, is everybody doing it wrong?
If I met the person who thought of these schemes I would happily smack them in the face.
Plymo said:
It's started on the M4... Went down there at 3am on Monday and the 50 signs were on the gantries. Heading east the fist gantry showing the limit is the one with the camera (what a coincidence, of course)
And what a waste of the expensive "variable" limit system!
Haven't been on the Port Talbot section yet but I'm assuming they will extend the average speed camera coverage as well.
Who in the Welsh government is worth contacting about this? Crap ideas like this make a mockery of the safety arguments and risk creating contempt even for justified limits, which might of course reduce safety
I live in the Wrexham area, and the stretch of the A483 where this is in force is apparently 'dangerous and an accident waiting to happen' And what a waste of the expensive "variable" limit system!
Haven't been on the Port Talbot section yet but I'm assuming they will extend the average speed camera coverage as well.
Who in the Welsh government is worth contacting about this? Crap ideas like this make a mockery of the safety arguments and risk creating contempt even for justified limits, which might of course reduce safety
Not driven it since the changes came in, but people are saying that those (few) who reduce to 50mph are getting overtaken by lorries and people joining the dual carriageway are doing 60mph+ and 'forcing' those in the left lane out into HGV traffic over taking in the outside lane.
Everyone else is of course taking no notice and driving at their regular 70mph+ speed, lambasting those obeying the speed limits.
Probably all a bit 'mumsnet' and 'daily mail', will have a drive that way over the next few days and see what's what.
One of the major problems with variable limits is the variable interpretation - 50 limits are, anything from 48, right up to 80 if you are the Romanian van I saw on the M6 the week before last - and the fact they cause traffic to bunch. Even if you attempt to maintain a safe gap it gets squandered by some lane-switching loon and, worse still where lanes are narrowed for road works, because the three lanes never seem to run at the same speeds, you get HGVs undertaking too. This is bad enough with the narrow lanes but when the foreign truck are doing their usual failure to multi-task (driving whilst brewing coffee or w
king, or whatever) and start weaving, it is exceedingly dangerous. You only have to look at the M6 Twitter feed to see the frequency of accidents.
We simply do not have enough road capacity. 'Smart' roads are a stupid, expensive solution.
king, or whatever) and start weaving, it is exceedingly dangerous. You only have to look at the M6 Twitter feed to see the frequency of accidents.We simply do not have enough road capacity. 'Smart' roads are a stupid, expensive solution.
Digga said:
One of the major problems with variable limits is the variable interpretation - 50 limits are, anything from 48, right up to 80 if you are the Romanian van I saw on the M6 the week before last - and the fact they cause traffic to bunch. Even if you attempt to maintain a safe gap it gets squandered by some lane-switching loon and, worse still where lanes are narrowed for road works, because the three lanes never seem to run at the same speeds, you get HGVs undertaking too. This is bad enough with the narrow lanes but when the foreign truck are doing their usual failure to multi-task (driving whilst brewing coffee or wking, or whatever) and start weaving, it is exceedingly dangerous. You only have to look at the M6 Twitter feed to see the frequency of accidents.
We simply do not have enough road capacity. 'Smart' roads are a stupid, expensive solution.
i think the biggest problem is our "smart" roads are run by dumb people. king, or whatever) and start weaving, it is exceedingly dangerous. You only have to look at the M6 Twitter feed to see the frequency of accidents.We simply do not have enough road capacity. 'Smart' roads are a stupid, expensive solution.
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