Sigalert - a warning broadcast by radio stations telling of unusual or hazardous traffic conditions.

What's so unusual about that? All radio stations broadcast those kind of messages. But, a sigalert is unique to Southern California. Here is the explanation by Todd S. Purdum of the New York Times, in May, 1997.

Each weekday morning in the City of Angels (Los Angeles, CA) the rat-atat-tat of traffic reports crackles over car radios every six minutes, a jumble of jackknifed big rigs, three-car pileups, and stop-and-go rubberneckers in the realm where the automobile is king.

Then, when you least expect and can least afford it, you hear the S-word: "A Sigalert on the eastbound Santa Monica Freeway has traffic backed up from Fairfax." "A Sigalert on the San Diego Freeway just south of the airport." "A Sigalert on the Pacific Coast Highway."

A Sig-a-what?

Every Southern California driver knows what it portends.

"You're about to be delayed," says Layna Browdy, corporate communications manager for the Auromobile Club of Southern Califronia, who hears plenty of Sigalerts in her 100-mile daily round trip between her home in Irvine and downtown.

The term is such a universal touchstone that when the Pacific Park amusement arcade opened on the spruced up Santa Monica Pier, it christened its blue-and-yellow bumper car ride the Sigalert.

But what does it mean?

"I always thought it meant signal alert," actor and director Rob Reiner confessed before allowing that he knew the truth that most Angelenos don't. That the Sigalert was the brainchild of a broadcast pioneer named Loyd C. Sigmon. [At the time this article was written Mr. Sigmon was alive and well and driving a cream-colored Lincoln Continental with a hands-free cellular telephone and a vanity license plate that proclaim, "SIGALRT."]

"It catches your attention," the dapper Sigmon explained in an interview. "It's just a little diferent."

In fact, the Sigalert, like so many things in Southern California, began as a bid for attention in 1955, when Sigmon was partners with singing cowboy Gene Autry in Golden West Broadcasting. Golden West was the parent of radio station KMPC [and KTLA-TV] "and looking for ways to get more listeners" in the face of growing competition from other radio stations and television.

The Cold War was on, the Eisenhower administration was building the interstate highway system, and what better way to grab a listener's ear than with instantaneous notification of public disasters, emergencies, and delays?

The Los Angeles Police Department said it could not be bothered to call every radio station. But Sigmon had a solution.

As an overseer of radio communications for the European Theater (in World War II), "Sig" Sigmon had spent hours searching Nazi transmissions.

He proposed that stations install receivers that would be activated by a signal from police headquarters and then record the officer's bulletin for immediate broadcast. The department's chief, William H. Parker, slightly skeptical, said, "We're going to name this damn thing Sigalert."

On Labor Day weekend in 1955, the first bulletin went out, Sigmon recalled.

Since then, the original shortwave system has been supplanted by computer links, and the California Highway Patrol has taken over its administration. But the basic idea is the same.

The official Highway Patrol definition of a Sigalert is 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.

But the term has passed into far wider use, and it appears in the New Shorter Oxford English Dictionary. In the past couple of years alone, a check of local newspapers shows an FBI agent warned that a raid on medical and legal clinics should serve as "an official Sigalert to those involved in insurance fraud," and a sportswriter described a sneeze-prone golfer as having "Sigalert sinuses."

"When I was doing traffic I got more questions about, 'What the hell is a Sigalert?' than anything else," said Bill Keene, who pioneered radio traffic reporting and retired in 1993, after 37 years on the air and who is credited by Sigmon with helping popularize the term. "But nobody knew just where it came from. It got really big in the mid-70's."