The new marching orders for federal workers during snowstorms this winter: Leave the office by the time we tell you to go home — or stay put until we say the roads are safe.

In the first overhaul of its bad-weather policy in 14 years, the government is vowing to avoid the chaos that unfolded Jan. 26, when thousands of drivers were trapped in gridlock for as long as 12 hours. Most workers left the office just as snow began falling at rush hour.

The Office of Personnel Management (OPM) now makes a 4 a.m. announcement about whether the federal government will close for the day or open late. But it’s planning to make the decision even sooner, sometimes as early as the previous evening, depending on the forecast.

The agency also plans to change its procedure for closing down when a snowstorm threatens to foul the evening rush hour. Current policy calls for dismissal two hours early, a time that varies based on when employees start work. Now there would be a deadline when the government would close. Workers would either leave by that time or be encouraged to “shelter in place” until it’s safe to drive.

No one would be forced to stay at work, however.

“Our basic point is, it’s a recommendation we strongly suggest,” said Dean Hunter, OPM’s emergency management chief. “You’re not going to have security guards go through the building and tell people, ‘You’re going to have to leave now.’ ”

About 300,000 people work at federal agencies in the Washington region, so decisions about their workdays have an outsize effect on traffic in what is already a congested area. Thousands of local companies follow the government’s lead on when to open or close.

OPM is expected to give the policy — which the agency describes as a draft — final approval next week after consultation with regional officials with the Council of Governments (COG).

COG has been meeting for seven months to improve traffic flow during weather emergencies. The Washington Post obtained details in advance.

Even workers who commute by Metro would be urged to leave by the deadline or stay put, Hunter said, to limit the load on the transit system. When the storm subsided, personnel officials would distribute a message “indicating it’s safe and proper to use these methods of transportation,” he said.

Personnel officials said it is too early to say whether they would provide cots, coffee and food if workers had to stay at the office.

“If you have a massive snowstorm and the roads are not passable, it could make a major difference in the success of keeping people safe,” said Montgomery County Council member Phil Andrews (D-Gaithersburg-Rockville), who is leading the effort at COG. Plans call for a team of emergency management experts to provide better and faster updates about weather, road and transit conditions — and governments to speed up their communication.

The new federal snow policy would be the linchpin in the plan.

On severe-weather days, Personnel Director John Berry will decide whether to open the government after a 3 a.m. conference call with dozens of local, state and federal officials. He will open the government, close it, open with an option for unscheduled leave or telework, or open with a delayed arrival or departure.

Critics said sheltering in place is not enforceable.

“Unless you chain someone to their desk, it’s not going to happen,” said Tim Firestine, Montgomery’s chief administrative officer. “How do you deal with the human nature of it? If I have a four-wheel-drive, I’m going to jump in it.”

Lon Anderson, managing director for AAA Mid-Atlantic, said “the key to that is education of commuters — getting people to buy into it. It’s going to take some significant effort.”

Carl Rauscher, a management analyst for the National Archives in College Park, said the new policy could “potentially . . . be really confusing.” But he said he would welcome early notice on whether to come to work.

He and his wife commute together and need to ensure that someone is home to care for their 13-year-old daughter.

“A day’s notice would give us a chance to coordinate,” he said. “As long as we know ahead of time, we’d have a chance to plan.”

In recent years, the growth of teleworking in the government has made snow planning more flexible: The government stays open, but work gets done from home. But despite new mandates from Congress and the Obama administration to allow more employees to telework, just under 40 percent do it, most of them infrequently, according to this year’s government survey of the workforce.

The government doesn’t make weather-related decisions lightly.

When it declares a snow day, it still bears the $77 million a day in federal payroll costs.

Even when the government permits unscheduled leave — allowing employees to take a vacation day — as many as half of the area’s federal workers stay home, which also costs tens of millions of dollars.

Staff writer Steve Vogel contributed to this report.