In the vein of this question How to say Tefilas HaDerech while on the road alone -- I am wondering whether it is appropriate to say a prayer or make a brocha while concurrently operating a car. Potential halachic issues include threat to life, and the question of integrity of one's kavana.
(Inspired by seeing a handwashing poster which stated without citation that the Shulchan Aruch prohibits making a blessing while engaged in "work" [sic].)