The act of driving a motor vehicle down the interstate while tired or intoxicated and "bumping" back and forth between the rumble strips when you pass out. Just like in bumper bowling, the ball reaches it's final goal, but not without some assistance from going in the gutter.
"Man I was way to tired to be driving last night. I was bumper bowling all the way home."
The tendency of a pedestrian preoccupied with another task (e.g. talking on a cell phone, fiddling with a portable music device) to veer left and right across the sidewalk, unknowingly blocking faster-walking pedestrians attempting to overtake them.
So named for the similarity between the perpetrator's movements and those of a bowling ball in the eponymous ten-pin bowling variant, in which the lane's gutters are blocked by bumpers to prevent gutterballs.
"I just missed the Muni because I couldn't get around some Bluetooth idiot who was hella bumper bowling."