In New York City, congestion pricing leads to marked drop in pollution

> Particulates issued from tailpipes can aggravate asthma and heart disease and increase the risk of lung cancer and heart attack. Globally, they are a leading risk factor for premature death.

Minor nitpick, but tailpipes aren't the primary source of emissions. The study is about PM2.5[0]. which will chiefly be tires and brake pads. Modern gasoline engines are relatively clean, outside of CO2, though diesel engines spit out a bunch of bad stuff.

[0] https://www.nature.com/articles/s44407-025-00037-2

Is that true for slower moving vehicles? I can't imagine there's a lot of brake dust generated by stopping & starting in the 0-10 mph range.

Afraid the intuition is somewhat incorrect.

Similar to with tire wear what's important to emissions is the amount of force that has to be applied to decelerate and how often it occurs. At highway speeds it's far less of an issue, but in slow speed urban environments with lots of stop start driving and high vehicle densities it's a real problem.

See for instance https://uk-air.defra.gov.uk/assets/documents/reports/cat09/1...