With major highways reopened after the monumental weekend storm, snowplows turned to secondary roads Monday, but it may be days before they reach into the warren of residential streets to excavate homeowners snowbound since Friday.

Metro said that it planned to resume full rail service on all but the Silver Line at 5 a.m. Tuesday and that bus service would be expanded, although still extremely limited, as the capital region struggled to dig out from under more than two feet of snow.

The news about Metro’s revival after a weekend hiatus was a welcome relief for many who were eager to return to work and school after the novelty of the massive storm began to wear off.

Although most school systems said they would remain closed Tuesday — and some, like Arlington County, through Wednesday — many workplaces were prepared to call on their employees to return. But the federal government announced just before 10 p.m. that its offices in the D.C. region will remain closed Tuesday.

Capital Weather Gang's Jason Samenow has your weekly forecast and reports on just how much snow fell in the D.C. area during "Snowzilla." (Jason Samenow,Ashleigh Joplin/The Washington Post)

Most U.S. post offices in the region reopened, but delivery service was spotty because mail carriers often could not reach homes and businesses

Local authorities continued to urge drivers who had been snowbound since Friday to avoid unnecessary trips so that plowing could continue.

The work of snow crews was complicated by the fact that the more than two feet of snow that fell in many places could not be easily shoved aside. Much of the snow had to be hauled off to an open space, creating mountains that would take weeks or months to melt away.

Officials were largely noncommittal about when they expected plowing to be finished. District officials said they hoped to have the downtown area cleared enough to be “back to business” by Tuesday, when D.C. government planned to reopen.

With the vast task, authorities were prioritizing, and the neighborhoods where people actually live and park their cars were often not at the top of the list.

In the District, Michael Czin, spokesman for Mayor Muriel E. Bowser (D), said “we want to get the main thoroughfares clear” and “we want to make sure the most likely Metro [bus] routes are up and running.”

D.C. Mayor Muriel Bowser warns residents not to park on snow emergency routes as cleanup efforts begin after a major blizzard hit the East Coast. (wusa9)

“And we’ll continue to make our way through the residential streets,” Czin said.

A giant snow melter is on its way from Indiana, a convoy of trucks is heading to the District from Connecticut and the city is seeking federal assistance, said Chris Geldart, the city’s director of homeland security and emergency services.

“Twenty-four inches of snow across 4,400 miles [of roadway], we have a lot of snow we’re going to be moving,” Geldart said.

Hope for a big thaw was dimmed by the forecast, which suggested a touch of rain or snow Tuesday and Wednesday that could create icy conditions and the possibility of more snow later in the week.

Maryland Transportation Secretary Peter K. Rahn warned that the weather could cause dangerous conditions. He said that on interstates and U.S. highways, “we have bare roads . . . for at least two lanes in each direction. We don’t have all of the shoulders cleared,” Rahn said.

Maryland Gov. Larry Hogan (R) said Monday that “local authorities particularly, will need time to dig out.”

Montgomery County offered no promises of when all its residents would be freed from impassible residential streets.

“It’s not going to be over today. It’s not going to be over tomorrow. We’ll just have to see when it will be over,” said county spokesman Patrick Lacefield.

On Monday, county plows began to move through larger residential roads, he said. Smaller neighborhood streets will come next.

“We have our crews working 24/7,” Lacefield said. “We’ve still got a ways to go.”

Virginia said its interstates will be largely, though not completely, cleared by Tuesday’s morning rush.

“We’ll have to see how much progress we make overnight,” said Jennifer McCord, spokeswoman for the Virginia Department of Transportation. “It’s just so much more snow than we usually get.”

Virginia officials said they have made significant progress on clearing streets in subdivisions, but they offered no timetable for when all neighborhood roads would be traversable.

Though many people wanted to break out from the snow, there remained a degree of patience.

“The streets will get plowed when they get to it,” said Ed Rich, who said the first plow reached his Rockville street at 10 a.m. Monday. “I have no complaints. I think people need to be patient. Major roads need to be plowed first.”

In Silver Spring, Laura Hagmann, 53, said she’d heard the distant beeping of a snowplow in her neighborhood Monday morning but didn’t expect to see one on her residential street for another day.

“I am sympathetic,” she said. “There is a lot of snow out there, and it just takes time to remove it.”

But by Tuesday, she said, “my patience will be waning.”

Small dramas and acts of kindness played out through Monday’s sparse but steady commute, which served as something of an easy practice run. But the relatively minor disruptions seen Monday may be amplified into major bottlenecks, as larger numbers of drivers potentially head back out Tuesday.

At one downtown corner Monday, two large red plows driven by city contractors scraped their way down I Street one after the other. But the trail of heavy, dirty snow that sloughed off their plow blades ended up blocking the northbound lane of a major cross street (17th Street), forcing cars to swerve into the oncoming traffic lane to get by. Later, a follow-up plow got stuck on a snow mound while turning to clean up the mess.

One good Samaritan offered Josephine Jimenez, an investment consultant, a hand as she climbed over the snowbank blocking the sidewalk. “I was hoping they’d scoop a little bit more,” Jimenez said. “I’m from San Francisco, so this is all different for me.”

One continuing danger posed by the snow sent seven people to the hospital in Fairfax with carbon monoxide poisoning Sunday night after the exhaust vents inside their apartment building’s furnace rooms became clogged with snow.

“This is a huge concern,” said Capt. Randy Bittinger of the Fairfax County fire department. “We certainly don’t want people to go out on their roofs, but they should make sure those vents are also clear.”

At least nine people in Maryland, Virginia and the District have died in incidents related to the blizzard, according to figures released Monday. Several more deaths are being investigated.

Virginia State Police said six deaths are linked to the storm – one traffic fatality in Chesapeake, and five due to hypothermia in the city of Hampton and the counties of Wise, Charles City, Gloucester and Henry.

Not included in this list is the death of a man Sunday in Leesburg who police said suffered an apparent heart attack while walking home from a store through waist-high snow. A Virginia State police spokesman said this death is among several awaiting rulings from the medical examiner’s office, so the number could climb.

In Maryland, two deaths have been confirmed by authorities as snow-related. A man in his 60s died Saturday after shoveling snow in Fort Washington, in Prince George’s County, and a 49-year-old man died in Abingdon, northeast of Baltimore, also while shoveling snow.

Police in Maryland are investigating two other possibly storm-related deaths. The body of a man described by police as homeless was found Sunday in Laurel, in a snowbank off U.S. 1, and a woman was found earlier that day lying on a street in Hampstead, about 30 miles northwest of Baltimore.

There was one storm death reported in the District, that of an 82-year-old man who D.C. fire officials said died Sunday after shoveling snow on a residential street in Northeast.

Some flights resumed Monday at the region’s three major airports, which were largely shut down over the weekend. But passengers were encouraged to check their flight’s status before heading to the airport.