SigAlert Born in L.A.

The Los Angeles SigAlert, created in 1955 by Loyd C. Sigmon (pictured), refers to the closing of a single lane of traffic for 30 minutes or more and has become a valuable public service to the city’s rush hour commuters. The first of these high-tech, radio road bulletins announced a derailed, downtown train and requested emergency medical assistance. So many medical personnel rushed to the scene that they created a larger traffic jam than did the original accident itself.