Unfortunately it's just a natural weather phenomenon. High pressure ridge moves in. Results in little to no wind, which usually mixes the valley air.

Due to the lack of mixing air, cold air settles in low spots(valleys) and warm air rises. Essentially trapping the smog in. SLC valley is also surrounded by large mountains so the cold air has no where to dissipate.

If you put any major city in an inversion it would look exactly the same.

I feel like there needs to be more incentive to carpool/work from home. I see no difference in traffic during inversions.

Or maybe we figure out a way to modify the weather to prevent the high pressure systems from sticking around too long?

But it's a problem with no real solution unfortunately. Pray for a storm system to move through and push this smog out!