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Comment by dataflow | Hacker News Reader

> I just cannot wait for at least 50% of cars to be electric, hope I live long enough to see it.

> It is just so disgusting out there on the roads for pedestrians and cyclists.

I would caution against getting too excited. "Non-exhaust emissions, which include tire, brake and road surface wear, account for 90% of all particulate emissions from vehicles." [1]

[1] https://www.cnn.com/2022/08/16/world/tyre-collective-micropl...

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If I recall, that's kind of deceptive. Particulate emissions from tires are much larger particles that fall out of the air much more rapidly and aren't nearly as linked to bad health compared to combustion products.

I guess I'm confused what specifically they were finding disgusting on the road. I thought they meant smog, which is mostly particulate matter?

The concerning bits are mostly “Ground-level ozone, sulfur dioxide, nitrogen dioxide and carbon monoxide” which are all gases. https://en.wikipedia.org/wiki/Smog

Particulate matter from tires is more concerning if you live next to a major highway. However in cities it’s almost all combustion byproducts with significantly lower tire ware due to low speeds + lots of idling at stoplights. Which is why catalytic converters made such a huge impact.

I get that those are concerning, but "disgusting for pedestrians and cyclists"? O3, SO2, and CO are all invisible, and even SO2 is not something people see at a close distance AFAIK. Moreover I don't understand how they would be noticeably different for drivers vs. pedestrians/cyclists. Only the particulate emissions (smoke etc.) are things that would seem noticeably different, no?

Exercise means significantly faster breathing and thus significantly more exposure per minute. Road cyclists can and should use a mask which helps vs particulates, but they can’t easily avoid these gasses.

Also, while most cars have some air filtration for the cabin the quality of that filtration can vary quite a bit. It can be well worth an aftermarket upgrade.

> ... particles that fall out of the air much more rapidly and aren't nearly as linked to bad health ...

... unless you eat seafood[0]?

[0] https://news.ycombinator.com/item?id=37726539

There's is also pulling out an actual source rather than hand waving conjecture based on random opinion pieces.

https://www.bts.gov/content/estimated-national-average-vehic...

Gasoline cars 2020: Exhaust 0.005 g/mile. Brakes 0.003 g/mile, tires 0.001 g/mile.

So exhaust + brakes produce 8 times as much PM2.5 as tires. So the argument but 'but but EV's are heavier and produce more PM2.5 than gasoline cars' doesn't cut it.

Also I've seen references that show natural gas heating isn't nearly as clean as portrayed.

Because exhaust emissions are non particulate. That’s like saying in this bag with 200 blue balls and 10 red balls, 90% of the red balls are red.

That stuff is mostly not airborne and much heavier than the sooth that coats buildings and lungs equally. And of course the toxic fumes that you breath. If you have small kids, the toxicity at knee level is a lot higher if you are near a busy road.

If you want a sneak preview of the future, visit Oslo. Traffic is mostly clean and quiet there.

What about non-particulate emissions?

Sorry, what do you mean by non-particulate emissions? Emissions that... aren't particles? Like broken glass from car windows?

Things like ozone and carbon monoxide and sulfur dioxide.

Oh I see. But this is about non-exhaust emissions... does e.g. rubber rolling on the road generate gases like carbon monoxide? I feel like I'm missing something.

I think 20after4 forgot we were talking about electric vehicles...? Or more charitably, they're talking about the supply chain? Unsure as well.

At least for me, >90% of the annoyance caused by motorized vehicles is due to their exhausts.

In my old city there was a spot where cyclists used to use the bus lane, combined with a stop. I would often have to wait behind the bus. Each time the bus started, it caused a bunch of smelly exhausts that I would breathe in directly. Absolutely horrible smell and also not a great feeling. The city then made a test with electric buses, and the bad smell was gone.

Buses are the second worst only after mopeds, which have tiny motors so can't efficiently burn the gases. They are not just noisy but also leave a wake of horrible smell.

Has anyone attempted to regulate this? Seems like the kind of thing that maybe no one has even bothered trying to improve.

Tires would be very very different if they weren’t allowed to generate particles.

Yes exactly and I’m wondering if that path has been explored.

Would be a great federal challenge program. We might accidentally make tires that last forever.

Technically we regulate emissions, yet we have people rolling coal; technically you have to drive safely and not speed and yield to pedestrians and yet we have people getting killed on our roads daily. It’s pretty hard to keep the auto industry in check when we’re all so brainwashed in the US (and because of our poor urban planning)

This is not like that though. Granular citizen behavior is hard to regulate. Product aspects are easy to regulate.

Are there many cars driving around without airbags because regulation is hard? No, not really.

There is no brake dust from EVs, they use regen to recapture energy.

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