The Georgia Emergency Management Agency had — but did not use — a system to send weather and traffic alerts directly to people’s cell phones during the crippling Jan. 28 snowstorm, The Atlanta Journal-Constitution has learned.

Georgia received federal approval to use the technology, which resembles the “Amber alert” system for missing children, in 2012. It puts a big, type message on the phone’s home screen, accompanied by a distinctive sound and a vibration. The alert goes to cell phones within a given geographic area automatically, without the users having signed up for the service.

In theory, alerts might have urged people to stay at home on the day of the storm, not to hit the roads as gridlock developed, and provided shelter and safety information through the night.

“We had the system. It had never been tested, configured or used for weather and traffic alerts,” said GEMA spokesman Ken Davis.

That changed abruptly in the wake of last month’s storm. On Monday, the governor’s office announced that the system will be deployed in future weather emergencies.

“The governor has determined that a weather-related crisis rises to that level of urgency, so that’s why we’re expanding the use of this system,” Deal spokesman Brian Robinson told the AJC in an email.

The national system, known by the acronym IPAWS, is just one of many ways technology can revolutionize how officials, companies and individuals share information in times of crisis. In the era of cell phones (especially smartphones), mobile apps, Twitter and Facebook, disaster managers can get detailed, localized, up-to-the-minute information to people who are in harm’s way. No more dependence on tornado sirens or generalized radio and TV alerts.

Emerging technologies “can actually keep you from getting into a bad situation, and also help you get out of one quickly,” said Laura Myers, a senior researcher for the Center for Advanced Public Safety at the University of Alabama.

But, as Georgia’s recent misadventure shows, every innovation comes with its own challenges — including but not limited to the foresight of the people responsible for deploying it.

Putting the hardware and software in place is just Step 1. It must be configured, tested and explained to the public. Decision makers must determine when and how to use it. And there’s a whole emerging science devoted to crafting messages that are concise, clear and authoritative — in the case of IPAWS, within the limit of 90 characters, 50 fewer than the longest tweet.

What’s the best way to communicate vital information to people so that they will react in ways that enhance their safety? What verbs work best? What colors communicate urgency? How many times must information be repeated to be absorbed? At what point does warning become over-warning, breeding complacency?

Challenges aside, the IPAWS system has been used to good effect already in other states.

It was used to warn people in the Northeast during Hurricane Sandy. Last year, the system helped spur the evacuation of an inflatable soccer dome in Connecticut before a tornado tore apart the structure. When floods hit parts of Colorado last September, transportation officials sent an emergency alert to residents in hard-hit areas, warning them that certain roads were unstable and could give way.

“It’s already saving lives,” said Michael Gerber, a National Weather Service meteorologist.

IPAWS (the Integrated Public Alert and Warning System) is a public-private partnership between phone carriers (AT&T, Sprint, T-Mobile and Verizon, among others) and federal agencies such as the Federal Emergency Management Agency, the National Weather Service and Federal Communications Commission.

The weather service generally takes the lead in sending alerts containing straight weather information. The role of states, counties and cities will more often be to give direction on how people should respond.

Nationwide, about 200 local governments have been approved to use it. In metro Atlanta, Fulton County is developing plans to deploy the technology.

Davis said few states have actually put the system to use, because officials are still working out operational and training issues. “FEMA reports their IPAWS training is minimal and introductory, at best, and state EMAs are asking many questions about procedures, how and when to use it, draft messages, what software to use or not use, scenarios within which to use it, etc.,” Davis wrote in an email.

Of course, in addition to government-generated alerts, people can choose from hundreds of cell phone weather apps available on the marketplace. For Georgians, the WSBTV Channel 2 Weather App provides location-based severe weather alerts as well as constantly updated forecasts and 2HD weather radar that can zoom to the neighborhood level.

It, like some other apps, taps into the GPS function on a smartphone, allowing the user to receive area weather reports wherever they are. Other apps get even more specialized: One, WeatherBug, touts its ability to measure the distance between a subscriber’s smartphone and the nearest lightning strike.

The value of such information from private sources is incalculable. But they largely rely on data gathered and disseminated by the federal government. And while private companies may make it part of their mission to help people stay safe, the responsibility for doing so rests with the agencies and officials paid with taxpayer dollars.

During metro Atlanta’s snow and traffic mayhem, thousands of people found the performance of those officials and agencies wanting. Trapped in cars, schools and elsewhere, they scrambled for information but found little that was useful on the state’s websites and apps.

Stuck at the intersection of I-75 and I-285, Charles Gay, an AJC deputy managing editor, turned to the state transportation department app. It estimated that roads in the area would be cleared by 3:15 a.m. The only problem: It was already 4 a.m.

Actual useful information arrived several hours later in a decidedly low-tech form: a couple of guys, one of them wearing University of Michigan sweat pants, walking down I-285 telling drivers that the best escape route was Cobb Parkway.

Technology was instrumental in bringing relief to many stranded by the storm, but the solutions often came from individuals who improvised.

On Facebook, more than 1,000 people joined a newly created “Snowed Out Atlanta Eastside” page. One woman used the site to plead for someone to help her diabetic sister, who was stuck in her car overnight without medication or food. Someone a few blocks away took her some food.

Stung by a hail of criticism for their performance during the recent storm, government forecasters and community decision-makers are scrambling to improve. Sometimes, perhaps, trying too hard.

On Thursday, the Georgia Department of Transportation had to apologize for overreacting to forecasts and posting messages on highway message boards about winter storm watches and warnings. There weren’t any.

When, how and how often to warn are not simple matters. Some cultures tend to act as a family unit, while others are more individualistic. For a message to be effective, those crafting it must understand how people react under extreme stress and how they process the language used by forecasters.

Confuse them with weather-speak about storm advisories versus storm watches, and they’ll tune out the alerts. Choose the wrong words, and the confusion can be measured in human misery.

Communication scientists have learned that people often need repeated messaging to get the point. But experts also worry about over-alerting the public, which can cause people to lose faith in the system.

One example: the National Weather Service used a mobile alert system to send out a flash flood warning throughout a county the size of Connecticut, when only one small area was affected. Worse example: The fire department in Palo Alto, Calif., outraged residents by using automated emergency alerts to announce its charity pancake breakfast.

“If we mess up the initial phase,” people will opt out of receiving alerts “and we will miss opportunities down the line to help people,” said Tarun Wadhwa, a blogger for Forbes on technology and public policy.

For now, many Georgians will have to adjust to receiving emergency weather alerts that they never signed up for. That might mean getting jolted awake at 4 a.m. by a jarring noise and a text from GEMA on their phones.

“It can be pretty creepy,” said Rebecca Jeschke, a digital rights analyst for the Electronic Frontier Foundation. “It can be disorientating and feel invasive.”

But better, perhaps, than spending the night huddled in an ice-bound car during SnowJam 2015.