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Comment by asdff | Hacker News Reader

Most emissions from modern vehicles these days comes from things like tire dust rather than tailpipe. What would be best for local street level pollution would probably be something like a lightweight rickshaw over a multiton EV.

https://www.theguardian.com/environment/2022/jun/03/car-tyre...

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Is that why the air is so bad in Mexico City and Los Angeles?

Remember during Covid when the sky’s turned blue in LA?

You’ve got to be careful on the Internet, people sort of just make it up as they go.

http://publichealth.lacounty.gov/eh/safety/criteria-air-poll...

But I do agree, more mass transit and fewer cars would be better.

The air really isn't that bad in LA most days, its improved substantially in recent decades but the meme of LA smog takes longer to die I guess. The geography of the place sometimes forms an inversion layer however, and on those days air quality is worse. Right now in particular, the air is almost perfect (1). It's still a farcry from living near a lot of industrialized agriculture in terms of aqi, or out in the great plains where you have ag then also west coast wildfire smoke tends to blow up and over the rockies and settle down. I can't speak for mexico city but I know they also have a similar inversion layer effect.

https://map.purpleair.com/1/mAQI/a10/p604800/cC0#10.12/34.06...

Looks good right now. LA still vies for the worst air pollution in the country.

https://en.m.wikipedia.org/wiki/Air_pollution_in_the_United_...

https://www.lung.org/research/sota/city-rankings/most-pollut...

Depends on where you put the probe in LA honestly. Downwind of the airport or the port are a different story than against the coast where there's almost always a prevailing wind blowing stuff inland. There are also hillside neighborhoods high enough were you can end up above the inversion layer sometimes. You look at some of the top hits of that list you see Bakersfield, Fresno, and Sacramento, all a fraction of the size of LA but they get such bad air from all the agriculture happening in the central valley.

How about trucks that literally emit black smoke? Plenty of them in NYC

Do any cities in America ban older vehicles? It's common in European cities.

For example in Copenhagen buses and lorries must be at most 8 years old. The fine is €1700.

https://urbanaccessregulations.eu/countries-mainmenu-147/den...

No, but in some cities or states older vehicles must pass smog inspections.

Those of course emit a lot more tailpipe emissions, but they aren't running rideshare either. If you have a consumer gas car with efi and a cat, the tailpipe is probably pretty benign compared to something from the 70s.

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