Sig Alert facts for kids

Sigalert is a special kind of traffic alert in California and other parts of the United States. It tells people about big problems that stop or slow down road traffic.

The California Highway Patrol (CHP) says a Sigalert is when one lane of traffic closes for 30 minutes or more because of an unplanned event. These alerts are shared on the CHP website, on radio and TV, and on electronic signs above freeways. The California Department of Transportation (Caltrans) has a slightly different idea: they say it's when two or more freeway lanes are blocked for two or more hours.

The word "Sigalert" was added to a dictionary in 1993. You might see it spelled in different ways, like "Sigalert," "Sig-alert," or "SIG Alerts."

What is a Sigalert?

A Sigalert is like an urgent message about traffic. It lets drivers know quickly about serious traffic jams or road closures. This helps people avoid the problem areas or find different routes.

These alerts are usually about accidents, big spills, or other events that make it hard for cars to move. They are meant to keep traffic flowing and drivers safe.

How Sigalerts Help Drivers

Sigalerts are very important for drivers in busy places like California. They give real-time updates on traffic conditions. This information helps people plan their trips better.

For example, if there's a big accident ahead, a Sigalert will warn you. You can then choose another road or wait until the problem is cleared. This saves time and reduces frustration.

How Sigalerts Started

Sigalerts began in 1955 in Los Angeles. Back then, more and more cars were on the roads. This led to many traffic accidents and big jams. Radio stations wanted to report traffic, but the police were too busy. They had to repeat the same information to many different stations.

A man named Loyd Sigmon came up with a smart idea in 1955. He worked for a radio company. During World War II, he had learned a lot about radio systems. He wanted to use this knowledge to solve Los Angeles's traffic problem.

Loyd Sigmon's Invention

Loyd Sigmon invented a special radio receiver and a tape recorder. When the police sent a specific tone, his device would automatically record their traffic message. This meant police didn't have to call each radio station separately.

The first devices cost about $600, which was a lot of money back then. The police chief liked the idea but said all radio stations needed to have the device. It couldn't just be for one station.

At first, about six radio stations installed Sigmon's receivers. When a message came in, a red light or a buzzer would tell the radio engineers. They could then play the police message right away, even if it interrupted their regular shows.

Early Uses of the System

One of the first big "Sigmon traffic alerts" happened on January 22, 1956. It warned about a train crash near Los Angeles's Union Station. The alert asked for doctors and nurses to help. However, too many people, including sightseers, drove to the scene. This actually made the traffic worse!

The very first SigAlert was actually on Labor Day weekend in 1955. At first, the police sent about one alert a day. Soon, other groups also used the system. They sent messages about things like gas leaks or even a ship crash.

Once, a pharmacist made a mistake with medicine. He used the Sigalert system to warn the customer, who heard the alert in time. The system was also used in 1963 to warn people about the Baldwin Hills Dam possibly breaking.

Sigalerts Today

In 1969, the California Highway Patrol (CHP) took over the Sigalert system from the Los Angeles Police Department. Now, Sigalerts are used all over California. They are only for traffic situations.

Radio stations still broadcast these messages. However, most stations now get the information from the CHP's website. They read the details themselves instead of playing the police dispatcher's voice.

CalTrans also uses the term "Sig-Alert." They often define it as any traffic problem that blocks two or more lanes of a freeway for two or more hours.

As of 2007, not all California radio stations use the exact term "Sigalert." For example, radio station KABC uses "KABC Traffic Alert." But many other stations, like KNX, KFI-AM, KRLA, KQED, and KCRW, still use the original "Sigalert" name.