My suggestion is to just stop doing it, especially if you start sleeping worse (the first symptom if you're affected). My life was ruined by not caring about living near a highway even though I easily had the money to get into a better apartment.
Now for the past 5 years (I'm 38 now) my life is about trying to find places with clean enough air, which is much harder and more expensive in winter time.
I'm always looking at experiments that reverse methylation damage, and hoping that those experiments succeed before I get cancer, but there's only 1 successful experiment so far, and I have no idea if it would help me.
The problem is that it all depends on your genes. For many people air pollution doesn't affect them..but I thought it doesn't affect me before it started.
Regarding living close to highways: air pollution close to them are much higher than farther away, and you spend a significant amount of time sleeping at home, so you if you are not lucky, you are affected.
Generally background noise is a good predictor of air pollution in my experience, just open the window, and if you hear cars all the time, you should look for another place to live.
I'm wondering how shorter the lifespan for me and others like me will be in the long run.
I'd say that's pretty bad but as the deaths are not instantaneous, the long term damage is difficult to quantify.