Yes, but aren't a lot of those pollutants localized? I was just at a national park which called out how air pollution was affecting lichens and other sensitive

Yes, but aren't a lot of those pollutants localized? I was just at a national park which called out how air pollution was affecting lichens and other sensitive life in the area, but...the part of the park with informational hikes bordered a highway where huge trucks passed by every few minutes. We forbid offroad vehicles from driving through wetlands for this sort of reason; those environments are very sensitive to the pollution, noise, erosion, etc. But we put freeways damned near everywhere. I dunno. I agree, it doesn't seem like enough, but what can we do? Tear up all our roads and rebuild them on a carefully-planned "pollution grid"? And even then, the BLM allows grazing and hunting on most of their lands which is another deeply-ingrained tragedy of the commons. Good luck getting rid of those methane-rich cow farts in the area when everyone feeds their herds off of the 'free' land. And good luck keeping 4x4s away when hunting is allowed.