(interrogative) asked when the leadership structure of a particular group or initiative is unclear, often posed in response to a perceived vacuum, as in “We’re getting conflicting directions from regional presidents on our new sales approach, we just need to know who’s driving the bus here”; can also be utilized as a descriptor, as in “I’ll be driving the bus for our annual conference”; like head of the snake, this phrase attempts to describe authority while simultaneously dulling any imperious overtones that might inhere in such a role through the use of lighthearted metaphor