When I was a child and my mother started thinking out loud about "going home," she meant driving to Grandma's house a thousand miles away. This trip from Ohio to Nebraska with two parents, five children, and sometimes a dog did not happen in our unairconditioned family sedan without considerable planning and effort. Just packing the car strained family cordiality and tested my father's training as an engineer. His plan was always the same: Be on the road shortly after midnight and drive all night so that the younger children would sleep through the first several hundred miles. Sometimes we would stop for sightseeing at such places as Lincoln's Tomb in Springfield, Illinois, or to admire the St. Louis Gateway Arch. Always we were struck with awe as we crossed the "big bridge" over the might…