So what? It's anti-social behavior. What thought does the deleted diesel truck driver give to his fellow citizens, whose otherwise reliable respiratory systems are weakened and made more susceptible to failure by toxic fumes and particulates?
The fact is, emissions regulations in many ways have nothing to do with health or clean air. I don't drive a diesel truck myself so its not like I'm trying to defend my own behavior or anything. I'm a former automotive engineer who is unfortunately very familiar with the regulations and how nonsensical they are.