Having a smoking/non-smoking section in a restaurant is stupid. Smoke does expand, and will fill the whole room reguardless of if it's in the non-smoking section or not.

When you're in a car and someone lights up a ciggarette and rolls down the window, some of the smoke still will travel around the car and affect the other passengers.

Either your building is going to allow smoking, or it isn't. I think that smoking on patio's and such at certain places is fine though. As for bars, if you're going to be drinking you're killing yourself anyways so smoke shouldn't really matter to you.

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