From anecdotal observation, it seems that drivers who smoke are more likely to be speeders, and have other bad driving behaviors. I had been thinking about this for some time, noticing that when I’m tail-gated or cut-off, the driver usually has a ciggy in their hand or lips. This applies to both men and women. It was really brought home when I took my daughter to Driving School for an accident (non-smoker, don’t know if the elderly driver who ran into her was, or not - she was a brand new driver at the time, for what its worth, she allegedly made an improper lane change) - most of the class was clustered outside puffing away, right up to class time.
Don’t know if it is the distraction of smoking, or the personality type that chooses one risky behavior - smoking - despite overwhelming evidence, will also choose another risky behavior - bad/fast driving. My guess goes with the second choice.
Yes, I lifted this from myself near the end of another GD thread about speeding, but it was kinda off-topic: http://boards.straightdope.com/sdmb/showthread.php?threadid=57622