5 ms·

while switching to electric vehicles likely reduces break dust, such switch would simultaneously increase dust from tires, since increased acceleration. The lat

while switching to electric vehicles likely reduces break dust, such switch would simultaneously increase dust from tires, since increased acceleration. The latter being already 80% of urban "particulate matter" pollution.

iguy 7y ago
And weight, presumably heavy vehicles wear through more rubber, and batteries are heavy.
- brownbat 7y ago
  Weight. This is so much about vehicle weight. I think the heavier EVs hit a crossover point because of regenerative braking, but weight does set them back, that's one of the whole points of this study: https://www.sciencedirect.com/science/article/abs/pii/S135223101630187X https://www.sciencedirect.com/science/article/abs/pii/S13522... This is a curve though. We could almost simplify the problem and only look at what heavy trucks generate and ignore all the cars completely, it'd be a non-crazy approximation.
DenisM 7y ago
I don’t think Nissan Leaf is particularly good at neck-breaking acceleration, and it probably outnumbers the drag-racing Teslas. Even then, a Tesla isn’t particularly speedy in traffic.
- Geeflow 7y ago
  I often drive a Renault Zoe which also isn't a sports car. I frequently leave sports cars behind at the traffic light. From 0-30 kph even the small/cheap electric cars are sport cars. And it is terribly tempting to develop a pedal-to-the-metal habit. So I assume tire dust will increase significantly in the cities.
  - sandworm101 7y ago
    Rate of acceleration isnt the issue. You may make more dust per second but so long as you are getting to the same end speed, and not spinning tires, the total amount of acceleration is the same. In my experience, over braking is the greater problem. Front tires degrade more quickly than rears. The average driver brakes far harder than they accelerate.
Reason077 7y ago
Tyre wear does release particulate matter, but it's mostly heavy, large particles that end up on the road and get washed away by weather. With the exception of tunnels, where heavy particles are constantly being churned up from the road surface and re-circulated into the air, tyre and brake wear is a relatively minor contributor to urban air pollution.
- brownbat 7y ago
  > tyre and brake wear is a relatively minor contributor to urban air pollution Why do you say that? Would love to know more, but all the research I've read lists them as significant contributors, second only to resuspension, each now exceeding tailpipe emissions on both PM 10 and PM 2.5. https://www.sciencedirect.com/science/article/abs/pii/S135223101630187X?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S13522... https://dot.ca.gov/-/media/dot-media/programs/research-innovation-system-information/documents/preliminary-investigations/brake-wear-emissions-pi-a11y.pdf https://dot.ca.gov/-/media/dot-media/programs/research-innov... As an aside, we'd probably agree that vehicle weight is the mediating factor across all of these sources, regardless of the ratios from one type to the other. Massive load hauling trucks are generating a disproportionate share of emissions of all types, this is not really about making sedans a little more efficient.
  - Reason077 7y ago
    Claims that tyre/brake particles exceed exhaust emissions are inevitably referring to particulate mass, not particulate count. One large particle can weigh as much as millions of nanoparticles, but is far less dangerous. Exhaust nanoparticles (sub-PM2.5) are small enough to penetrate the respiratory system, diffuse to the blood stream, and cross the blood-brain barrier. Here in London, some of the most obviously polluted and stinking roads are those where the traffic barely moves at all - lots of slow moving or idling vehicles. There isn't a great deal of brake or tyre wear when vehicles are standing still!
    - brownbat 7y ago
      > Claims that tyre/brake particles exceed exhaust emissions are inevitably referring to particulate mass, not particulate count Huh, all the studies I've read and linked are comparing like with like within particle size categories. Idling considerations are addressed in the modeling too. You seem fairly unshakable here, but the topic seems well researched and the results are pretty unambiguous to me.

iguy 7y ago

And weight, presumably heavy vehicles wear through more rubber, and batteries are heavy.

brownbat 7y ago
Weight. This is so much about vehicle weight. I think the heavier EVs hit a crossover point because of regenerative braking, but weight does set them back, that's one of the whole points of this study: https://www.sciencedirect.com/science/article/abs/pii/S135223101630187X https://www.sciencedirect.com/science/article/abs/pii/S13522... This is a curve though. We could almost simplify the problem and only look at what heavy trucks generate and ignore all the cars completely, it'd be a non-crazy approximation.

DenisM 7y ago

I don’t think Nissan Leaf is particularly good at neck-breaking acceleration, and it probably outnumbers the drag-racing Teslas. Even then, a Tesla isn’t particularly speedy in traffic.

Geeflow 7y ago
I often drive a Renault Zoe which also isn't a sports car. I frequently leave sports cars behind at the traffic light. From 0-30 kph even the small/cheap electric cars are sport cars. And it is terribly tempting to develop a pedal-to-the-metal habit. So I assume tire dust will increase significantly in the cities.
- sandworm101 7y ago
  Rate of acceleration isnt the issue. You may make more dust per second but so long as you are getting to the same end speed, and not spinning tires, the total amount of acceleration is the same. In my experience, over braking is the greater problem. Front tires degrade more quickly than rears. The average driver brakes far harder than they accelerate.

Reason077 7y ago

Tyre wear does release particulate matter, but it's mostly heavy, large particles that end up on the road and get washed away by weather. With the exception of tunnels, where heavy particles are constantly being churned up from the road surface and re-circulated into the air, tyre and brake wear is a relatively minor contributor to urban air pollution.

brownbat 7y ago
> tyre and brake wear is a relatively minor contributor to urban air pollution Why do you say that? Would love to know more, but all the research I've read lists them as significant contributors, second only to resuspension, each now exceeding tailpipe emissions on both PM 10 and PM 2.5. https://www.sciencedirect.com/science/article/abs/pii/S135223101630187X?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S13522... https://dot.ca.gov/-/media/dot-media/programs/research-innovation-system-information/documents/preliminary-investigations/brake-wear-emissions-pi-a11y.pdf https://dot.ca.gov/-/media/dot-media/programs/research-innov... As an aside, we'd probably agree that vehicle weight is the mediating factor across all of these sources, regardless of the ratios from one type to the other. Massive load hauling trucks are generating a disproportionate share of emissions of all types, this is not really about making sedans a little more efficient.
- Reason077 7y ago
  Claims that tyre/brake particles exceed exhaust emissions are inevitably referring to particulate mass, not particulate count. One large particle can weigh as much as millions of nanoparticles, but is far less dangerous. Exhaust nanoparticles (sub-PM2.5) are small enough to penetrate the respiratory system, diffuse to the blood stream, and cross the blood-brain barrier. Here in London, some of the most obviously polluted and stinking roads are those where the traffic barely moves at all - lots of slow moving or idling vehicles. There isn't a great deal of brake or tyre wear when vehicles are standing still!
  - brownbat 7y ago
    > Claims that tyre/brake particles exceed exhaust emissions are inevitably referring to particulate mass, not particulate count Huh, all the studies I've read and linked are comparing like with like within particle size categories. Idling considerations are addressed in the modeling too. You seem fairly unshakable here, but the topic seems well researched and the results are pretty unambiguous to me.