The Freeway’s Guardian Angels
Robert L. Bertini
Everyone knows that major sources of freeway congestion are the “incidents,” including accidents, that block free traffic flow. Other troubling incidents include stalled engines, cars that have just run out of gas, debris fallen from trucks, flat tires, strayed animals, and other random events. According to one estimate, half of all congestion is relate to incidents. With vehicles stopped on the roadway, one incident can cause others, something leading to chain reactions involving many cars. So motorists and traffic officials alike consider incident-mitigation a critical objective.