The Man Behind The SigAlert

Don Barrett reports at LARadio.com that Loyd C. Sigmon (above right, with Gene Autry), the one-time KMPC-AM engineer who came up with the famed "SigAlert," has died. He was 95.

Traffic-obsessed Angelenos have learned to curse the ubiquitous SigAlert, which the CHP describes as "any unplanned event that causes the closing of one lane of traffic for 30 minutes or more, as opposed to a planned event like road construction, which is planned separately."

Sigmon first came up with the idea in 1955, building a contraption that would allow the LAPD to use a special frequency to alert radio stations of a traffic emergency. (The CHP took over in 1969).

Recalls this site, a pretty thorough history of the SigAlert: The first "Sigmon traffic alert" was broadcast on September 5, 1955. It had the unintended effect of CAUSING a traffic jam, as the message was sent out requesting any available doctors and nurses to respond to a train derailment outside L.A.'s Union Station. Nobody realized how many doctors and nurses would rush to the scene and tie things up even worse.

Initially, about one alert a day was issued by LAPD, but soon other nearby agencies were calling in messages they wanted broadcast. Not just traffic-related either. There were rabid dog reports, at least one message from a druggist who had made a potentially fatal error in filling a customer's prescription, gas leaks, and the impending Baldwin Hills Dam collapse in 1963.

The system had caught on quickly, and the positive publicity was not lost on Bill Parker. According to which version you want to believe, it may have been the Chief himself who gave it its name, when he mentioned to an aide, "We'll probably call the damn thing 'SigAlert.'"