Late Sunday night, my wife and I drove from Sacramento, Calif., to Los Angeles. We figured that it would be wise to leave Sacramento in the early evening to avoid traffic. At 7 p.m., we climbed into the car and headed for Interstate 5, the major highway connecting Northern California and Southern California. For the first five hours of the drive, things went as planned. The highway was relatively clear, and we sailed along happily at 80 mph. Then we saw it. A sign. A large orange sign reading: Freeway Closed Ahead, 11 p.m.-4 a.m. It was too late to...