Entirely unashamed anti car propaganda, and the more the better.

[maomao]

Pretty sure that if everyone on board had a car and drove, it would result in fewer particulates being inhaled.

I'd like some workings out on that one. Seems unlikely to me.

 

[Artaxerxes]

I have moaned about this before but when did indicating become optional?

Just seen three cars out of five in a traffic snarl go left without indicating first

 

[platinumsage]

I'd like some workings out on that one. Seems unlikely to me.

Euro III 2000.10 heavy-duty diesel engine standard is 0.1 PM (g/kWh).

As to how much particulates would increase if it's badly maintained and producing lots of visible soot, this article would suggest upto +85% for nozzle and needle wear, +50% for a dirty air cleaner and +85% for excessive oil consumption. This would give 0.22 PM.

The average car is 12.2 years old. Let's assume 20 people on the bus each drive in an average car instead, that would be Euro 5 standard of 0.005 PM (g/km!).

Obviously real-world would be different. I suspect the smoky bus would be a lot worse and the cars massively better than stated limits (because most of them would be petrol cars), but that's some workings out for you.

If you have better data or can be arsed to do more calcualtions please feel free to share.

 

[teuchter]

That Puma is about half an inch taller than a Mondeo, about a foot shorter, considerably lighter, and minus a fairly large number of CO2g/km.
I don't find myself agreeing with platinumsage often, but the nonsense of applying the label "SUV" to anything that's half an inch higher off the ground than a Nissan Micra is bollocks. The aging public have spoken and they want the comfort and convenience of higher seats. The vast majority of the "SUV"s sold today are a supermini jacked up by an inch. Just as efficient (the height does knock a touch off the MPG, but it's margin of error level and no-one wants to sit on the floor for maximum drag coefficient), pretty much the same size.

The car I have lined up to replace our Note in a few years (CX-30) is larger, about the same height, and get an additional 10% extra mileage on the motorway. How is it bad that it's bigger? It's also one of those "SUV's that are a regular car with an extra inch in height (because we're old now and the Mazda 3 is a bit low-ish).

As often happens on this thread , this is written from a "won't anyone think of the elderly drivers" perspective rather than "won't anyone think of elderly people".

The height of cars is very relevant to pedestrians (and cyclists). Here are eye level heights for standing adults:



Cyclists' eye levels are quite similar.

Until relatively recently, most European cars were lower than most adults' eye level. That meant that most people could see over the top of most cars parked along streets. That means more visibility for things like crossing roads (including at designated crossings) and it also contributes to the general feel of a street with cars parked along it. I took the Mondeo as a bit of an arbitrary benchmark, but according to the dimensions posted further up the thread, it's 1460mm high. Compare that to the numbers in the eye level chart. The Puma is "only" 77mm higher (about 3 inches) but at 1537mm it's already higher than the 50% percentile of women. Relatively small increases in height, around this level, can be significant for humans. In case anyone's forgotten what they are, they are the things that are often in cars but also the things that walk around on pavements. Some of them are elderly, many of them find crossing roads difficult or prefer streets where they can clearly see the other side.

Width is important for the amount of physical street space taken up. Again only a small increase in width becomes significant if you multiply it by 4 (2x kerbside parking and 2x moving traffic lanes) and then subtract it from the space left over for a cyclist. It means that in general more space is needed for parking. Space that could be used for other things.

The cross sectional area of a car is determined by its width x height. Greater cross sectional area means more air resistance means more energy to move. It's just physics. Maybe a modern "SUV" is more efficient and less polluting than a 10 year old "standard" car but so what? The comparison should be with a modern "standard" car. That's the choice that's being made.

We have infrastructure that is designed for what used to be the "standard" car size. We have various rules and assumptions built on that too. It's a genuine problem if a large number of cars start to become bigger (which is what's happening). If buyers of large vehicles don't want their tyres deflated maybe they should lobby for measures which would let them have large vehicles in return for some changes to how we accomodate cars in the public realm. For example, all streets currently with kerbside parking on both sides to be changed to one side only. All two-way streets below a certain width re-designated as one way. Vehicles over a certain size disqualified from on-street parking anywhere. Once they have succeeded in such measures being implemented, the problem will have been mitigated and they can get back to shopping for their giant death machines.

 

[kabbes]

^^ That is a really excellent and informative post

 

[maomao]

Euro III 2000.10 heavy-duty diesel engine standard is 0.1 PM (g/kWh).

As to how much particulates would increase if it's badly maintained and producing lots of visible soot, this article would suggest upto +85% for nozzle and needle wear, +50% for a dirty air cleaner and +85% for excessive oil consumption. This would give 0.22 PM.

The average car is 12.2 years old. Let's assume 20 people on the bus each drive in an average car instead, that would be Euro 5 standard of 0.005 PM (g/km!).

Obviously real-world would be different. I suspect the smoky bus would be a lot worse and the cars massively better than stated limits (because most of them would be petrol cars), but that's some workings out for you.

If you have better data or can be arsed to do more calcualtions please feel free to share.

Aside from pulling the number 20 out of your arse, and making best case assumptions for all the cars while making worst case assumptions for the bus (the sliver of truth in which is a reflection of the resources put into private transport compared to public) it's also 80 tryes and 20 sets of brakes instead of four and one, six times the road space etc.

 

[teuchter]

Even if the numbers for the bus argument added up: it would only make sense if your starting point was that public transport is unnecessary - everyone should be responsible for their own private transport.

If we agree that there should be public transport, then the bus needs to be there in some form - that's a given. Obviously, the more efficient and less polluting the bus can be, the better (and buses have improved a lot in the recent past), so sure, argue about whether we should be investing in new buses.

But once the bus, in whatever form, is there, it's simply not an option to shift all the passengers to cars, and remove the bus. Maybe 60% of the bus passengers also own a car, and could use it instead. But shifting them all to car doesn't decrease pollution, it increases it. Even if the cars produce a fraction of the pollution the bus does, per occupant.

On the other hand, if you have a 50% full bus, even a polluting one, filling the remainder up with passengers who otherwise would have used their cars (even low-pollution ones) is almost certainly going to reduce pollution overall.

 

[Artaxerxes]

As often happens on this thread , this is written from a "won't anyone think of the elderly drivers" perspective rather than "won't anyone think of elderly people".

The height of cars is very relevant to pedestrians (and cyclists). Here are eye level heights for standing adults:

View attachment 353604

Cyclists' eye levels are quite similar.

Until relatively recently, most European cars were lower than most adults' eye level. That meant that most people could see over the top of most cars parked along streets. That means more visibility for things like crossing roads (including at designated crossings) and it also contributes to the general feel of a street with cars parked along it. I took the Mondeo as a bit of an arbitrary benchmark, but according to the dimensions posted further up the thread, it's 1460mm high. Compare that to the numbers in the eye level chart. The Puma is "only" 77mm higher (about 3 inches) but at 1537mm it's already higher than the 50% percentile of women. Relatively small increases in height, around this level, can be significant for humans. In case anyone's forgotten what they are, they are the things that are often in cars but also the things that walk around on pavements. Some of them are elderly, many of them find crossing roads difficult or prefer streets where they can clearly see the other side.

Width is important for the amount of physical street space taken up. Again only a small increase in width becomes significant if you multiply it by 4 (2x kerbside parking and 2x moving traffic lanes) and then subtract it from the space left over for a cyclist. It means that in general more space is needed for parking. Space that could be used for other things.

The cross sectional area of a car is determined by its width x height. Greater cross sectional area means more air resistance means more energy to move. It's just physics. Maybe a modern "SUV" is more efficient and less polluting than a 10 year old "standard" car but so what? The comparison should be with a modern "standard" car. That's the choice that's being made.

We have infrastructure that is designed for what used to be the "standard" car size. We have various rules and assumptions built on that too. It's a genuine problem if a large number of cars start to become bigger (which is what's happening). If buyers of large vehicles don't want their tyres deflated maybe they should lobby for measures which would let them have large vehicles in return for some changes to how we accomodate cars in the public realm. For example, all streets currently with kerbside parking on both sides to be changed to one side only. All two-way streets below a certain width re-designated as one way. Vehicles over a certain size disqualified from on-street parking anywhere. Once they have succeeded in such measures being implemented, the problem will have been mitigated and they can get back to shopping for their giant death machines.

 

[Chz]

As often happens on this thread , this is written from a "won't anyone think of the elderly drivers" perspective rather than "won't anyone think of elderly people".

The height of cars is very relevant to pedestrians (and cyclists). Here are eye level heights for standing adults:

View attachment 353604

Cyclists' eye levels are quite similar.

Until relatively recently, most European cars were lower than most adults' eye level. That meant that most people could see over the top of most cars parked along streets. That means more visibility for things like crossing roads (including at designated crossings) and it also contributes to the general feel of a street with cars parked along it. I took the Mondeo as a bit of an arbitrary benchmark, but according to the dimensions posted further up the thread, it's 1460mm high. Compare that to the numbers in the eye level chart. The Puma is "only" 77mm higher (about 3 inches) but at 1537mm it's already higher than the 50% percentile of women. Relatively small increases in height, around this level, can be significant for humans. In case anyone's forgotten what they are, they are the things that are often in cars but also the things that walk around on pavements. Some of them are elderly, many of them find crossing roads difficult or prefer streets where they can clearly see the other side.

Width is important for the amount of physical street space taken up. Again only a small increase in width becomes significant if you multiply it by 4 (2x kerbside parking and 2x moving traffic lanes) and then subtract it from the space left over for a cyclist. It means that in general more space is needed for parking. Space that could be used for other things.

The cross sectional area of a car is determined by its width x height. Greater cross sectional area means more air resistance means more energy to move. It's just physics. Maybe a modern "SUV" is more efficient and less polluting than a 10 year old "standard" car but so what? The comparison should be with a modern "standard" car. That's the choice that's being made.

We have infrastructure that is designed for what used to be the "standard" car size. We have various rules and assumptions built on that too. It's a genuine problem if a large number of cars start to become bigger (which is what's happening). If buyers of large vehicles don't want their tyres deflated maybe they should lobby for measures which would let them have large vehicles in return for some changes to how we accomodate cars in the public realm. For example, all streets currently with kerbside parking on both sides to be changed to one side only. All two-way streets below a certain width re-designated as one way. Vehicles over a certain size disqualified from on-street parking anywhere. Once they have succeeded in such measures being implemented, the problem will have been mitigated and they can get back to shopping for their giant death machines.

That's half insightful and half bonkers with zero concession to reality.

 

[teuchter]

That's half insightful and half bonkers with zero concession to reality.

Such is the nature of this thread but what specifically do you think is bonkers? Is it the idea that people could accept that their individual desire for a bigger car, when part of a general pattern, has a wider impact, which should therefore be mitigated or restricted in some way? And that they would voluntarily take appropriate action? If course it is, which is why they'll just continue to whine about lentils deflating their tyres.

 

[Chz]

It would take me at least a half hour to pick out what I agree and disagree with and formulate a rational response, so please don't take offense in my laziness of just not being arsed. But if I'm to pick out one thing - the small suvs that are the most popular things (pumas, konas, jukes, etc) are barely any larger than the superminis they've replaced. Why is the line here? Cars have been getting larger, generation upon generation for 50 years. At least. The Puma is taller than the Mondeo, but it's still narrower and presents less aerodynamic area. Why do we not slash a Mondeo? Surely it's larger than most people need?

 

[teuchter]

It would take me at least a half hour to pick out what I agree and disagree with and formulate a rational response, so please don't take offense in my laziness of just not being arsed. But if I'm to pick out one thing - the small suvs that are the most popular things (pumas, konas, jukes, etc) are barely any larger than the superminis they've replaced. Why is the line here? Cars have been getting larger, generation upon generation for 50 years. At least. The Puma is taller than the Mondeo, but it's still narrower and presents less aerodynamic area. Why do we not slash a Mondeo? Surely it's larger than most people need?

Actually I thought the least bonkers bit of what I wrote was relating car height to eye level.

Cars under about 1500mm, most adults can see over the top of them. Much more than that, and significant numbers of adults can't.

We can argue about exactly where to draw the line. A tyre slasher with an eye height of 1500mm might judge a Mondeo to be "not unusually large" and a Puma to be "large".

If you don't want your tyres slashed, perhaps it would be wise to consider those percentile statistics in relation to the height of whatever vehicle you are considering buying.

It doesn't really matter if there's a bit of inconsistency about where each tyre slasher draws the line - what's important is that it creates some kind of downward pressure on car size preference amongst purchasers.

Is it true that cars have been getting bigger for 50 years? This chart suggests that height was relatively stable until the late 90s. Width seems to have started increasing in the late 80s.

 

[platinumsage]

Actually I thought the least bonkers bit of what I wrote was relating car height to eye level.

Cars under about 1500mm, most adults can see over the top of them. Much more than that, and significant numbers of adults can't.

We can argue about exactly where to draw the line. A tyre slasher with an eye height of 1500mm might judge a Mondeo to be "not unusually large" and a Puma to be "large".

If you don't want your tyres slashed, perhaps it would be wise to consider those percentile statistics in relation to the height of whatever vehicle you are considering buying.

You think people should yield to the car slashers and buy longer, heavier, more polluting and inefficient cars like Mondeos instead of Pumas, just to satisfy someone’s eye height fetish?

It doesn't really matter if there's a bit of inconsistency about where each tyre slasher draws the line - what's important is that it creates some kind of downward pressure on car size preference amongst purchasers.

It only creates downward pressure on car height, but it creates upward pressure on car length, car weight, car inefficiency and car pollution.

If the tyre slashers had a logic that was internally consistent, I might not support them but at least I could say fair play they’re taking direct action in support of their professed beliefs.

However, currently they’re leafleting about climate change and various other factors, but they’re not targeting cars on that basis. They’re actually encouraging people to go against their stated aims by ditching efficient, safer, hybrids for long, heavy, dangerous polluting diesels.

If they can’t be arsed to work out what sort of cars they should target to further their aims, how can they expect the car buying public to choose cars based on those aims?

 

[mojo pixy]

You think people should yield to the car slashers and buy longer, heavier, more polluting and inefficient cars like Mondeos instead of Pumas, just to satisfy someone’s eye height fetish?

Yeah I don't think it's a 'fetish', it's to do with more pedestrians not being able to see over / beyond cars, which is a road safety issue. But you know this.

Plus the fetish, if that's a word we're using now, is the car .. the power, the prestige, the sounds and smells, the aggressive frowny headlight arrays, the shiny paint, the groovy geometric wheel trims etc. Phwoar, eh?

 

[platinumsage]

Yeah I don't think it's a 'fetish', it's to do with more pedestrians not being able to see over / beyond cars, which is a road safety issue. But you know this.

Plus the fetish, if that's a word we're using now, is the car .. the power, the prestige, the sounds and smells, the aggressive frowny headlight arrays, the shiny paint, the groovy geometric wheel trims etc. Phwoar, eh?

Yeah ignore my substantive points and focus on one word choice, great stuff.

Nowhere in their literature does it mention not being able to see over the top of certain cars. I don't think the thought even occurred to them.

 

[mojo pixy]

Yeah ignore my substantive points and focus on one word choice, great stuff.

Well it's your word, and it's an interesting one. Speaks volumes actually. Says more than your 'substantive points' tbh.

Nowhere in their literature does it mention not being able to see over the top of certain cars. I don't the thought even occurred to them.

I'm not interested in the tyre deflaters, but if I gave them any thought it'd broadly be amusement. The height thing is true and important though, and you seem to be avoiding addressing it. Any thoughts, then? Any thoughts on whether the increasing size of cars on the roads is a plus or a minus for road users, specifically non-driving road users? Any thoughts on the psychology of MASSIVE CARS in the urban environment?

(you edited, oh well)

 

[platinumsage]

Well it's your word, and it's an interesting one. Speaks volumes actually. Says more than your 'substantive points' tbh.

I'm not interested in the tyre deflaters, but if I gave them any thought it'd broadly be amusement. The height thing is true and important though, and you seem to be avoiding addressing it. Any thoughts, then? Any thoughts on whether the increasing size of cars on the roads is a plus or a minus for road users, specifically non-driving road users? Any thoughts on the psychology of MASSIVE CARS in the urban environment?

(you edited, oh well)

Why capitalize MASSIVE CARS? Seems a bit weird when we're talking about Ford Pumas.

 

[mojo pixy]

Why capitalize MASSIVE CARS? Seems a bit weird when we're talking about Ford Pumas.

I'm not, I'm talking more generally about MASSIVE CARS, especially in the urban environment. Particularly

• the psychology of choosing them and
• their impact on the safety of non-drivers.

Still, good job on the err what was it?

ignore my substantive points and focus on one word choice, great stuff.

oh yes that's right

 

[platinumsage]

I'm not, I'm talking more generally about MASSIVE CARS, especially in the urban environment. Particularly

• the psychology of choosing them and
• their impact on the safety of non-drivers.

Still, good job on the err what was it?

oh yes that's right

Ok, I'm talking about the tyre twats and the fact their program of tyre vandalism will have the opposite effect of their published aims.

I couldn't care less whether a car is 1485mm high or 1521mm high. If you care so much about that maybe start a dedicated thread on the topic.

 

[mojo pixy]

If you care so much about that maybe start a dedicated thread on the topic.

Nah, this is that thread.

I'm talking about the tyre twats and the fact their program of tyre vandalism will have the opposite effect of their published aims.

Well,

If you care so much about that maybe start a dedicated thread on the topic.

On the other hand,

I couldn't care less whether a car is 1485mm high or 1521mm high.

And I couldn't care less about car tyres being deflated. Don't have a car, don't get your car's tyres let down, easy peasy.

There you go. Now I can ask about the psychology behind choosing a MASSIVE CAR, and the impact of increasing numbers of such vehicles on people who aren't driving them. I know ''other people's wellbeing" is a weird and uncomfortable area of reflection for many drivers (especially the kinds who choose MASSIVE CARS) but it bears some discussion imo.

Evidently not with you, though.

 

[platinumsage]

Nah, this is that thread.

Well,


On the other hand,

And I couldn't care less about car tyres being deflated. Don't have a car, don't get your car's tyres let down, easy peasy.

There you go. Now I can ask about the psychology behind choosing a MASSIVE CAR, and the impact of increasing numbers of such vehicles on people who aren't driving them. I know ''other people's wellbeing" is a weird and uncomfortable area of reflection for many drivers (especially the kinds who choose MASSIVE CARS) but it bears some discussion imo.

Evidently not with you, though.

Define MASSIVE first. Is a Puma MASSIVE? How about a Skoda Superb? A Toyota Aygo X?

 

[Boris Sprinkler]

Want another topping of actual facts that car drivers ignore and get really fragile if pointed out to them?

Pollution from tire wear 1,000 times worse than exhaust emissions | Tire Technology International

Air pollution from tire wear particles can be 1,000 times worse than what comes out of a car’s exhaust, Emissions Analytics has found. Harmful particle matter from tires is a

www.tiretechnologyinternational.com

 

[ElizabethofYork]

Anything higher or wider than a Mondeo is fair game.

 

[platinumsage]

Want another topping of actual facts that car drivers ignore and get really fragile if pointed out to them?

Pollution from tire wear 1,000 times worse than exhaust emissions | Tire Technology International

Air pollution from tire wear particles can be 1,000 times worse than what comes out of a car’s exhaust, Emissions Analytics has found. Harmful particle matter from tires is a

www.tiretechnologyinternational.com

Ridiculous nonsense though:

"it was found that the car emitted 5.8g/km of particles"

Think about that for a minute. In the 20,000 miles it typically takes to wear a car's tyres from 8mm of tread to 2mm, it produces 185kg of particles? That's several times more than the entire weight of all four tyres, despite only 6mm being skimmed off the treads.

A clue is elsewhere in the article "particles released into the air from brake wear, tire wear, road surface wear and resuspension of road dust during on-road vehicle usage – are currently believed to constitute the majority of primary particulate matter from road transport: 60% of PM2.5 and 73% of PM10."

So the headline should read "Pollution from tyre wear and lots of other stuff about the same as exhaust emissions", rather than "...1,000 times worse...".

 

[teuchter]

It only creates downward pressure on car height, but it creates upward pressure on car length, car weight, car efficiency and car pollution.

Before we go further can we just confirm that you agree the tyre slashers actions create a downward pressure on car height, or do you in fact want to do a U turn on your statement above?

 

[platinumsage]

Before we go further can we just confirm that you agree the tyre slashers actions create a downward pressure on car height, or do you in fact want to do a U turn on your statement above?

If it was effective it would create a downward pressure on height but not on any of the things the slashers profess to care about such as weight, CO2, pollution or whatever. Whether it is effective at all I have no idea. I suspect it is not.

It's quite funny that you've invented the idea that their campaign is actually about enabling people to see over the top of cars.

 

[Chz]

Ridiculous nonsense though:

"it was found that the car emitted 5.8g/km of particles"

Think about that for a minute. In the 20,000 miles it typically takes to wear a car's tyres from 8mm of tread to 2mm, it produces 185kg of particles? That's several times more than the entire weight of all four tyres, despite only 6mm being skimmed off the treads.

A clue is elsewhere in the article "particles released into the air from brake wear, tire wear, road surface wear and resuspension of road dust during on-road vehicle usage – are currently believed to constitute the majority of primary particulate matter from road transport: 60% of PM2.5 and 73% of PM10."

So the headline should read "Pollution from tyre wear and lots of other stuff about the same as exhaust emissions", rather than "...1,000 times worse...".

The tyres are more pliant than the road, but basic physics says the road is also ablating particles into the air and roads aren't made of puppies and lollypops either. Unfortunately, in the name of safety cars are much heavier and tyres much wider than they've ever been in the past. So this sort of pollution could be lost to noise in the past (especially since the cars polluted a lot more out the tailpipe), but it's becoming significant.

I think we're losing the essentials to semantics right now, even if it is partly my own fault.

 

[teuchter]

If it was effective it would create a downward pressure on height but not on any of the things the slashers profess to care about such as weight, CO2, pollution or whatever. Whether it is effective at all I have no idea. I suspect it is not.

It's quite funny that you've invented the idea that their campaign is actually about enabling people to see over the top of cars.

A U-turn it is, then.

I'm not inventing anything about their campaign - I am explaining why I am happy for them to use height as an identifier of vehicles that are appropriate for action. And why I don't particularly care about their, your, or anyone else's definition of an "SUV".

 

[platinumsage]

The tyres are more pliant than the road, but basic physics says the road is also ablating particles into the air and roads aren't made of puppies and lollypops either.

I think we're losing the essentials to semantics right now, even if it is partly my own fault.

No that was actual mass loss from tyres in these clown's experiment:

"As we were originally concerned that the mass loss levels would be too small to measure, we stacked the decks by choosing the cheapest tyres, ballasted the car heavily, chose a track with average surface quality and designed a test cycle with high speeds and much cornering. Driving a 2011 VW Golf 320kms at high road speeds on the track resulted in a mass loss of 1,844g which equates 5.8g per km."

Which if course is entierly irrlevant to particulate pollution. I suspect big lumps were falling off their tyres.

 

[platinumsage]

A U-turn it is, then.

I'm not inventing anything about their campaign - I am explaining why I am happy for them to use height as an identifier of vehicles that are appropriate for action. And why I don't particularly care about their, your, or anyone else's definition of an "SUV".

So you're happy for them to attempt to incentivize people to switch from Ford Pumas and Toyota Aygo Xs into larger, longer, heavier, more polluting saloon and estate cars which according to their campaign are not SUVs and so much more acceptable to own?

Their website is a joke, I can't even think of any nine-year olds who would write such tripe, so to call it childish would be unfair:

"How To Spot An SUV: SUVs and 4x4s are easy to recognize because they are much larger than ordinary cars, towering above them and taking up huge amounts of space."

How huge is the space that a Ford Puma takes up?