^^Just for arguments sake, cigarette smoke at close quarters is a lot more dangerous than the diffused vehicle smoke. Also from what I have read, the cigarette smoke is 10 times more polluting than a typical diesel exhaust.
Secondly Vehicles have become a necessity for our current way of life. Everyone uses them one time or the other, so there are no innocent bystanders with regard to this. Even then we look for ways to reduce emissions from vehicles. Why do we have so many standards and research going on regarding that. We don't want to create more pollution than needed to get our work done. And to add people do get judgmental about vehicular and industrial pollution.
By the same yard stick, cigarette smoking is an absolutely non essential form of pollution caused by a group of people in the society. Cigarettes are not a necessity and People can live without smoking (Unless they smoked so much that they got addicted to it and their brains will stop functioning without that). So your analogy still has major flaws