- How did SigAlerts begin?
- How an early SigAlert caused traffic
There’s a term you’ve probably come across more than once while traveling around Southern California: SigAlert.
It’s one of the best ways to keep on top of traffic delays in near real-time, but they’re also a harbinger of stress. If a SigAlert is issued on your route, good luck getting to your destination on time. There could be a car stalled on the freeway, a car crash or any number of other problems shutting down lanes.
But do you know why they're called SigAlerts? They actually started out as a radio tool.
How did SigAlerts begin?
Before SigAlerts lived online in an interactive map, and were issued by the California Highway Patrol, they came from a specialized radio receiver that broadcast recorded messages.
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In the early ‘50s, civil defense officials had been looking into how to make an alert system in case of an attack from the U.S.S.R., which became the brainchild of Loyd Sigmon, executive vice president at L.A.’s KMPC radio station.
The system was first officially tested in November 1954. In City Hall, officials pressed a red button that took KMPC off air and instead broadcast civil defense information to listeners. Think of it like a Cold War version of the emergency alert system — the idea was to get urgent updates out fast, like potential attacks or major flooding.
A number of Southern California broadcasters signed on to install the necessary equipment, including KNX. Devices were also installed at the offices of civil defense personnel to speed up the process.
Sigmon also thought of a more daily use for the system. He approached the L.A. Police Department with an idea: set up a process for police departments to call the station when major traffic jams occur. But that wasn't really feasible for officers to do every time.
It’s unclear how many times Sigmon customized devices to use the SigAlert system in different ways, but according to SigAlert researcher Harry Marnell, for the LAPD, he used a $600 shortwave receiver and tape-recording device that booted up with a special tone. The LAPD would receive details from other agencies and then press a button to record and send that special tone with the information to radio stations (like a high-stakes telephone game).
The system, which was put into widespread use in Greater L.A. on Labor Day 1955, was intended to tell the public about a range of concerns: major freeway tie-ups, smog alerts, fire, explosions, dense fog and “atomic” attacks.
Today, it’s just about major traffic delays. Relaying of emergency information lies with things like the emergency alert system. But Sigmon has gone down in history as pioneering a way for mass communication. He died in 2004 when he was 95.
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How an early SigAlert caused traffic
Ironically, a SigAlert sort of created a big traffic jam.
Did you know?
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Before Loyd Sigmon died, he was known to drive around in a cream-colored Lincoln Continental coupe with the vanity license plate “SIGALRT.”
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The Santa Monica Pier’s bumper cars are also named after Sigmon’s work, dubbed Sig Alert EV. Their website says "Our Sig Alert EV is a great way to blow off steam after an hours-long commute to the west side"
In January 1956, a major train derailment happened — the Santa Fe train wreck — and an alert went out asking for any available doctors and nurses to respond. But so many people responded — including nosy onlookers — that it turned into an even bigger mess.
Priests, who were asked to come for spiritual help, were caught in traffic or turned away because of the amount of people driving over.
The derailment killed 30 people and injured 117. But the LAPD’s use of the SigAlert called into question exactly how effective (or ineffective) it was to broadcast such requests for help without a way to control the traffic build-up.
The L.A. Times put out an editorial days after the wreck that called out local authorities for poorly managing the emergency.
And while it praised how the SigAlert brought a swift medical response, the editorial board wrote that “nobody had the wit to stop” the onlookers on the highways.
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FAQs
While many Californians might assume “Sig” is short for “Signal,” it's not. “Sig” was a person. Loyd “Sig” Sigmon was the chief engineer for radio station KMPC in Los Angeles. In 1955, he devised a plan to boost ratings by asking Los Angeles police to call him whenever there was a major crash.
Where did the term SigAlert come from? ›
Sigalerts are named after an early radio engineer in Los Angeles, Loyd Sigmon. You can read more about Loyd Sigmon and the history of Sigalerts on Wikipedia.
What is a SigAlert in Los Angeles? ›
Sig alert, Sig-alert or Sigalert in California, as well as other parts of the United States, means an incident that significantly disrupts road traffic.
Who invented the SigAlert? ›
It was created in the early '50s by Loyd Sigmon, a radio executive at L. A's KMPC station. During the Cold War, civil defense officials were looking into how to make an alert system, a project that Sigmon developed.
What is a SigAlert in police terms? ›
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.
Who owns Sigalert? ›
A SigAlert is a notification system used by the California Highway Patrol to alert drivers about incidents that disrupt traffic flow, typically on interstates or major roads. Whenever a freeway is closed due to a crash – that's a SigAlert. While many Californians might assume “Sig” is short for “Signal,” it's not.
Is there a Sigalert app? ›
The Sigalert iPhone app is simple to use, but packed with information: *** MORE THAN JUST RED/YELLOW/GREEN - Sigalert offers incredibly detailed speed information. Sigalert's users know when traffic is moving 25 miles per hour and when it's moving 40 miles per hour.
What is rush hour in Los Angeles? ›
Rush hour in Los Angeles is similar to other cities in the United States, with morning rush hour from 7–10 AM and evening rush hour from 4–7 PM. During these times, freeways are often congested with drivers commuting to and from work. Traffic can also be heavy on weekend nights heading into or out of downtown Los Angeles and Hollywood. M&Y Personal Injury Lawyers
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Some say that Thursdays between 4–7 PM are the most congested time on LA freeways, with drivers averaging 37 miles per hour. Others say that the worst morning for traffic is Thursday, with commute times also peaking on Tuesday and Wednesday mornings. Are rush hour times changing in Los Angeles post-pandemic?
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To avoid rush hour traffic, some recommend:
- Staying off the interstates during peak times
- Avoiding driving, especially on the highway, between 7–9 AM and 4–6 PM
- Using mass transit, such as the affordable subway system
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What is the anti gridlock zone in Los Angeles? ›
Anti-gridlock zones in Los Angeles are arterial streets where parking, stopping, or standing is prohibited during peak hours to reduce heavy traffic and prevent gridlock. The zones are marked with fire-engine red signs in all caps, and vehicles stopped in violation may be removed. Drivers caught in an anti-gridlock zone during rush hour may be subject to a $163 citation. Are LA's Anti-Gridlock Zones Being Enforced? Also What Are They | LAist
Oct 7, 2019
American Legal Publishing
7-3-121: PARKING PROHIBITED IN ANTIGRIDLOCK ZONES:
City of Los Angeles (.gov)
MOTION
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American Legal Publishing
SEC. 80.61. STANDING IN ANY ALLEY. - American Legal Publishing
(Amended by Ord. No. 173,880, Eff. 5/21/01.) (c) The Department shall promptly cause each ...
Transportation officials can establish anti-gridlock zones on any arterial street when weekday hourly traffic demand requires the removal of parking in the curb lane to add an additional lane for through traffic. The zones are typically in effect between 6 AM and 7 PM on weekdays, but drivers should pay attention to posted hours and move their vehicles before or when the restriction begins. There is no grace period at the beginning or end of the restricted hours. American Legal Publishing
7-3-121: PARKING PROHIBITED IN ANTIGRIDLOCK ZONES:
American Legal Publishing
SEC. 80.70. PARKING PROHIBITED OR LIMITED IN ANTI-GRIDLOCK ...
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City of Los Angeles (.gov)
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Disabled Person/Veteran placards and plates are not exempt from anti-gridlock parking restrictions, except for emergency repairs or activities authorized by the city with a permit. American Legal Publishing
SEC. 80.70. PARKING PROHIBITED OR LIMITED IN ANTI-GRIDLOCK ...
Chapter 1A_PDF. SEC. 80.70. PARKING PROHIBITED OR LIMITED IN ANTI-GRIDLOCK ZONES. (Added b...
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Who invented the orange traffic barrels? ›
Traffic cones were invented by Charles D. Scanlon, an American who, while working as a painter for the Street Painting Department of the City of Los Angeles, was unimpressed with the traditional wooden tripods and barriers used to mark roads which were damaged or undergoing repainting.
The Romans also erected stone markers at mile intervals to notify the passerby of distances covered or the number of miles to go to reach their destination. These markers were conveniently called milestones.
Who invented traffic flow? ›
The foundation for modern traffic flow analysis dates back to the 1920s with Frank Knight's analysis of traffic equilibrium, further developed by Wardrop in 1952. Despite advances in computing, a universally satisfactory theory applicable to real-world conditions remains elusive.
Why is it called SigAlert? ›
It comes from the last name of Loyd Sigmon, who invented the SigAlert in 1955. Back then, according to old newspaper clips, Sigmon was an executive at radio station KMPC-AM (710) in Los Angeles, which, like other radio stations at the time, was looking for ways to compete with just-blossoming television.
Why are police called 5-0? ›
“5-0” (pronounced five-oh) became a popular nickname after the television show Hawaii Five-O which aired from 1968 to 1980. “Five-o” referred to the Hawaiian police force in the show, based on Hawaii being the fiftieth state to join the union.
Why do they call cops one time? ›
Term used in many English-speaking countries, used because one looks at the police one time, so as not to attract attention.
Who invented the traffic stop? ›
While other inventors are reported to have experimented with and even marketed their own three-position traffic signals, Garrett A. Morgan was the first to apply for and acquire a U.S. patent for such a device. The patent was granted on November 20, 1923.
Who invented the traffic circle? ›
The traffic circle, also known as a roundabout, has multiple origins:
1790s
Architect and engineer Pierre L'Enfant proposed circular intersections in Washington, D.C.'s street layout, including Dupont Circle.
1854
The Place de l'Étoile roundabout was redone around the Arc de Triomphe in Paris, France.
1877
French architect Eugene Henard may have invented one-way circular intersections.
1905
American businessman William Phelps Eno designed Columbus Circle in New York City, which is considered the first circular intersection for the automobile era.
1930
German engineer Werner Ruchti designed the traffic circle in Long Beach, California, based on European models. Federal Highway Administration
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Modern roundabouts were first standardized in the United Kingdom in 1966 and have since become common around the world. They are considered safer than stop signs and traffic lights because the tight circle forces drivers to slow down. The Federal Highway Administration recommends roundabouts as one of 20 evidence-based safety countermeasures. Roundabout - Wikipedia
Modern roundabouts were first standardised in the UK in 1966 and were found to be a signif...
The History Of Roundabouts - Hotard & Hise
Apr 2, 2023 — The 1960s saw roundabouts developed in the United Kingdom. Countless other coun...
Who invented traffic lines? ›
June McCarroll (June 30, 1867 – March 30, 1954) is credited by the California Department of Transportation with the idea of delineating highways with a painted line to separate lanes of highway traffic, although this claim is disputed by the Federal Highway Administration and the Michigan Department of Transportation ...
Who invented the automatic oiler for trains? ›
Elijah McCoy received his first patent for an automatic lubricating device in 1872. Previously, engines had to be stopped before necessary lubrication could be applied. McCoy's invention allowed engines to be lubricated while they ran, saving precious time and money.