NATICK, Mass. — The workweek in the snow-clobbered Northeast got off to a slow and slippery start Monday as drivers encountered unplowed streets, two-lane roads reduced to a single channel and snowbanks so high it was hard to see around corners.

Many schools remained closed across New England and New York, and nearly 140,000 homes and businesses were still waiting for the electricity to come back on following the epic storm that swept in on Friday and Saturday with up to 3 feet of snow, claiming at least 15 lives in the U.S. and Canada.

For some, a new worry emerged: the danger of roof collapses as rain and warmer weather melt the snow.

Most major highways were clear, though a 10-mile stretch of Interstate 91 from just north of Hartford to the Massachusetts line closed in both directions for more than an hour because of ice. Many secondary roads still had a thick coating of ice and snow, and big piles of snow blocked sight lines at intersections and highway ramps, making turning and merging hazardous.

“It was definitely a struggle to get here,” said Dana Osterling, who lives in Leverett in western Massachusetts and commutes to Boston twice a week to attend Berklee College of Music. She and her six housemates shoveled for about three hours straight to free their cars Sunday.

Fernando Colon of South Windsor, Conn., was driving to work in heavy sleet on a two-lane highway that was down to one lane because of high snowbanks. “This is awful,” he said as he stopped to pump gas.

Hundreds of people, their homes without heat or electricity, were forced to take refuge in emergency shelters set up in schools or other places. About 136,000 homes and businesses – more than 110,000 of them in Massachusetts – had no power. That was down from a peak of about 650,000 over the weekend.

Brenda Stewart and her husband, Jim, of Marshfield, Mass., lost power Friday night. They built a fire and were passing the time reading and painting, but the monotony was setting in.

“The hardest thing is being forced to do nothing, having forced R&R,” said Brenda Stewart, a nurse. But she added: “When you’re a New Englander, you kind of hunker down and just do it.”

Driving bans were lifted and flights resumed at major airports in the region. The Boston-area transit system resumed full service Monday but told commuters to expect delays. The Metro-North Railroad resumed most commuter train service on its New York and Connecticut routes, while the Long Island Rail Road said riders could expect a nearly normal schedule.

On New York’s Long Island, Samantha Cuomo of Bay Shore was stressed out as her 40-minute commute to work turned into two hours. She called the roads “an absolute mess.” The group-home manager complained that the street near her work hadn’t been plowed and trees were down.

“That’s what people pay tax money for,” she said.

Some school systems canceled classes on Monday, including in Boston, Providence, R.I., and on Long Island, while some local governments told nonessential workers to take the day off.

Long Island was slammed with as much as 2½ feet of snow, which shut down roads, including the Long Island Expressway, where many people had been stranded overnight during the worst of the storm. A 27-mile stretch of the expressway was closed Sunday but reopened in time for the Monday morning commute.

Gov. Andrew Cuomo said more than a third of all the state’s snow-removal equipment was sent to the area, including more than 400 plow trucks and more than 100 snowblowers, loaders and backhoes.

“The massive amount of snow left behind effectively shut down the entire region,” he said.

Utility crews, some brought in from as far away as Georgia, Oklahoma and Canada, raced to restore power. In hardest-hit Massachusetts, officials said some of the outages might linger until Tuesday.

Boston recorded 24.9 inches of snow, making it the fifth-biggest storm on record in the city. The city appealed to the state and private contractors for more front-end loaders and other heavy equipment to clear snow piles clogging residential streets.

Rain and higher temperatures in the forecast for Monday could help melt the mess but also put extra weight on snow-covered roofs, leading to collapses. Officials said people should try to clear flat or gently sloped roofs – but only if they could do so safely.

“We don’t recommend that people, unless they’re young and experienced, go up on roofs,” said Peter Judge, spokesman for the Massachusetts Emergency Management Agency.

Officials warned of the danger of carbon monoxide poisoning.

In Boston, two people died Saturday after being overcome by carbon monoxide while sitting in running cars, including a teenager who went into the family car to stay warm while his father shoveled. The vehicles’ tailpipes had become clogged with snow.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.