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Pollution from tire wear is worse than exhaust emissions?

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Re: Pollution from tire wear is worse than exhaust emissions?

#281

Post by Gibbon1 »

salty_biscuits wrote: post #268
ratel wrote: post #164

Hold on: The claim is this: > "Using a popular family hatchback running on brand new, correctly inflated tyres, we found that the car emitted 5.8 grams per kilometer of particles." It does not seem to be a mistake: > "Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tyre wear emission is higher by a factor of over 1,000." A tire might way up to 15 kilograms f…

Rubber has a density of 1500 kg/m^3, a tyre wears about 5mm before it needs to be replaced. If I say a tyre has a radius of about 0.3 metres and a width of about 0.2 metres and plug this into the equation for an annular cylinder I get about 2kg of material lost between new and needs to be replaced per tyre. I don't know how long tyres last for most people, but I would guess about 50000km. So I would expect about 0.2…

I did the calculation in Freedom Units and converted to grams per km. Assuming tires last 60,000 miles or 100,000km and got 0.1 gm/km. So matches your analysis closely.

Notable I put 60,000 miles on my cars tires since I bought it. They are due for replacement kind of whenever.

Re: Pollution from tire wear is worse than exhaust emissions?

#282

Post by na85 »

Causality1 wrote: post #243
saiya-jin wrote: post #222

Earlier quoted context omitted.

That doesn't make sense to me either. Take a busy German highway (as I don't know the average load on US ones), easily 100k cars per day. There are parts of highways which don't get replaced for 20 years easily. Plus apart from tiny fraction of north europe (and maybe Canada?), nobody ever uses studs. Back of the envelope math tells me 1 km of highway would lose some 730 tonnes of asphalt, per year (so 14,600 tonnes…

A rough way to think about road wear is the weight over one axle to the fourth power times the number of axles.

That gives you a quantity of force^4. How does that translate to road wear?

Re: Pollution from tire wear is worse than exhaust emissions?

#283

Post by Gibbon1 »

njarboe wrote: post #208
mycall wrote: post #204

Earlier quoted context omitted.

I thought brake pads use asbestos which contribute to the noxious particles. I do think Vehicle-to-vehicle communications will eventually minimize the all the chicken necking, evening out the traffic and thus less breaking.

Electric vehicles have regenerative braking when not braking hard. This dramatically reduces brake wear.

Hybrids as well.

Re: Pollution from tire wear is worse than exhaust emissions?

#284

Post by fiblye »

runarberg wrote: post #270
labawi wrote: post #247

Earlier quoted context omitted.

Weight of a masonry hammer is nothing compared to the weight of a human, yet it can destroy concrete with ease. I'd guess it depends on how and how much you walk on what kind of pavement with what kind of studded shoes. Damage can realistically be imperceptible or ugly.

There are a lot more cars, running on much greater speed, for a lot longer distance, with much greater weight, then humans walking on spiked shoes. The masonry hammer runs on much greater speed, with much more force, a lot more often then the human steps on the peace of concrete being taken apart.

Concrete sidewalks are pretty fragile. Unless they're freshly laid, most that I see have cracks and pits to some extent (probably mostly attributable to cooling/heating and water). Some people also seriously drop their feet down hard when they walk, and if they've got little bits of metal sticking out from the bottom of their shoes, I imagine that damage adds up and doubly so if it slams down an existing crack.

Re: Pollution from tire wear is worse than exhaust emissions?

#285

Post by sjg007 »

toss1 wrote: post #165
sjg007 wrote: post #82

Earlier quoted context omitted.

It will be dose dependent.

Exactly. Question is, what is the dosing level that would cause harm, and what are the routes that this material takes that might rise to such a level, vs how much is, e.g., stuck on the pavement and washed into the ditch with every rain?

I think we know that living near major roads is bad for you. So to figure out the dose you'd have to measure it at different distances. Volume and type of traffic. If you live near a major road you probably want to run an air cleaner with a hepa filter and not go outside to much or on busy days.

https://www.lung.org/our-initiatives/healthy-air/outdoor/air...

Re: Pollution from tire wear is worse than exhaust emissions?

#286

Post by jl2718 »

dragontamer wrote: post #125
read_if_gay_ wrote: post #113

Earlier quoted context omitted.

You are missing that the cost of bike lanes isn't just in constructing and maintaining them. Adding bike lanes in cities means dropping car lanes because there's not enough space. That ends up creating potentially huge opportunity costs.

Not quite IMO. Anyone who has done any amount of virtual traffic engineering (aka: Factorio, City Skylines, OpenTTD) knows that intersections are where the bottlenecks are. Its incredibly difficult to design a max-throughput intersection. Roads have a huge amount of throughput, most "traffic" just gets stuck at offramps and traffic lights. Narrowing a road to make room for bike lanes is a lower cost than people might…

One effect that I’ve seen pretty consistently is that adding traffic lanes to a single-lane local road almost always slows down traffic. This is because every intersection needs a stop light.

Re: Pollution from tire wear is worse than exhaust emissions?

#287

Post by cheerlessbog »

na85 wrote: post #282
Causality1 wrote: post #243

Earlier quoted context omitted.

A rough way to think about road wear is the weight over one axle to the fourth power times the number of axles.

That gives you a quantity of force^4. How does that translate to road wear?

Empirical studies apparently find road wear matches a power law. Although it seems the exponent varies.

Here's a survey https://www.nzta.govt.nz/assets/resources/603/RR-603-The-rel...

Re: Pollution from tire wear is worse than exhaust emissions?

#288

Post by bigiain »

kungtotte wrote: post #173
ratel wrote: post #164

Hold on: The claim is this: > "Using a popular family hatchback running on brand new, correctly inflated tyres, we found that the car emitted 5.8 grams per kilometer of particles." It does not seem to be a mistake: > "Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tyre wear emission is higher by a factor of over 1,000." A tire might way up to 15 kilograms f…

They're torn up from the road and rubbed off from the tyres themselves. The majority is obviously coming from the road. There's been studies done here in Sweden since we've banned studded winter tyres in some areas of Stockholm in an effort to reduce road wear and improve air quality. I don't know of any sources in English off the top of my head though. The last time I read an article about it though (2+ years ago, d…

>They're torn up from the road and rubbed off from the tyres themselves. The majority is obviously coming from the road.

Not sure even that adds up to believable.

The Sydney Harbour Bridge is about 500m long between the pylons. It has "more than 150,000 cars per day" on it (according to the snippet from a google search). If all of that was from the road, that'd mean there's about 160 tons of road getting torn up per year. It looks to be ~30m wide on Google Sat view, and "google first hit" research indicates road base weighs 1.9tons per cubic meter. It's be losing almost 6cm of depth along the whole span every year if all those numbers hold, or 3cm per year if "only half" of that comes from the road and the rest from the tires. They don't resurface it anything like often enough for that to be true...

Re: Pollution from tire wear is worse than exhaust emissions?

#289

Post by pmiller2 »

Karrot_Kream wrote: post #276
pmiller2 wrote: post #214

Earlier quoted context omitted.

It’s not all about throughput. Taking away car lanes in favor of bike lanes usually takes away parking as well. While that certainly has the desired effect of reducing car traffic to the area, it also increases the difficulty and expense of travel to the area. We’re seeing this in Oakland now, where they’re putting in bike lanes and taking away parking, while simultaneously doing nothing about the limited public tran…

I mean, or you can ride a bike in these new bike lanes in one of the flattest and temperate climates in the US? Oakland is littered with cars along roads in every neighborhood you go on, and the police barely enforce anything resembling traffic code (due partially to complicated historical reasons). In some neighborhoods, I've seen duplexes with more land area in cars than living space (so is it a wonder that poorer…

Sure, you can ride a bike. Now, tell me how you would transport groceries for a family of 4, or how you transport the kids to doctor's appointments, for instance. What about people who physically can't ride a bike? What if I'm coming from 15 miles away?

Re: Pollution from tire wear is worse than exhaust emissions?

#290

Post by na85 »

cheerlessbog wrote: post #287
na85 wrote: post #282

Earlier quoted context omitted.

That gives you a quantity of force^4. How does that translate to road wear?

Empirical studies apparently find road wear matches a power law. Although it seems the exponent varies. Here's a survey https://www.nzta.govt.nz/assets/resources/603/RR-603-The-rel...

That's for rutting damage, which doesn't necessarily translate linearly to particulate formation/flaking.
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