When I was a small boy I was live baggage on family trips from the Northeast to visit the grandparents a thousand miles away in Indiana. There were no Interstate highways – just the promise of the Pennsylvania Turnpike with its four smooth concrete lanes and many child-pleasing tunnels. The rest of the way was two lanes, small towns, and diners with steamed-up windows. Constantly in the way were highway trucks, only lately powered by weak-but-economical six-cylinder Diesel engines making 160 horsepower. Drivers knew what was next on their routes,…