I never clench my pipe right out in front of my face. That's just too much of a neophyte look IMO. I clench off to the side. If an explosive force went off in front of me, most likely my pipe would just get knocked to the side. But heck, we eat, drink, text, and take pictures as we drive. Unless you are just learning to drive or too old to remember where you were going, one should be just fine.
But, then again, I live in an area where if I do see other people on the road, we are moving like 10 MPH, but mostly we are on the road by ourself if we are going any faster than that.