Despite there being 7 billion of us, we seem to struggle with paying attention to more than one problem at a time.
Compared to those two, though, coal power plants are dirty as hell, and I’d take equivalent amount of car emissions to generate the same power over coal any day.
"One of its biggest shortcomings is that it only works at a fairly high temperature. When you start your car cold, the catalytic converter does almost nothing to reduce the pollution in your exhaust." [1]
And when it's cold the car usually starts at someone home around where other people live and that's where the pollution ends up.
For diesel engines that operate at lower temperatures this is even worse.
Particulate pollution from highways and major roads is definitely a real issue and there have been studies done showing a lot of health problems result from living 250-500m or closer to such a road.
But if we’re talking about a modern emissions-compliant gas/petrol ICE vs a coal power plant I’m not sure how that shakes out. Coal power emissions are estimated to have massive health effects that affect millions as well.
(Of course, best solution is electric car powered by nat gas, nuclear, or renewables which don’t emit particulates at all...)
Not that I want to argue in favour of coal plants; we still need to get rid of them just for the CO2. Same goes for ICEs.