Almost every morning, I take the kids and the dog for a walk around the block.
Sometimes, I'll push my luck and do the "big" 1-mile loop around our neighborhood, which once was considered the "small" loop relative to the "big" 4-mile loop ... but then we had children. That's when we realized that walking 4-miles with young children - who insist on walking themselves - can take the better part of a week.
Inevitably it happens that once we are midway around the block - or the farthest possible point from our house - those children that insisted on walking and haven't caught a ride in the double stroller alongside Henry, will plop themselves down on the sidewalk and take a rest. That's when I realize that maybe purchasing a quad stroller still might not be a bad idea.
I know for a fact that the double BOB wasn't designed to hold four kids.
The only thing that is more difficult then pushing four children in a stroller designed for two, while walking a dog - is when I let the kids take their bikes and scooters on the walk ... and wind up carrying those, too.