ATLANTA: The unyielding cold spell gripping much of the nation was expected to hang on tight over the weekend, though some areas that saw snowfall during the week were expected to have drier weather.

Busses are encrusted in ice and snow at the back lot of a bowling alley in the Omaha, Neb., suburb of Elkhorn, where a fire was being put out, Thursday, January 7, 2010. [Agencies]

In Atlanta, more accustomed to winter temperatures in the low 50s, a glaze of ice coated roads Friday after light snow overnight melted and froze. And authorities said the continuing freeze called for renewed caution on the roadways.

Nearly 30 cars piled up in a pre-dawn crash near Hartsfield-Jackson Atlanta International Airport.

In Alabama, packed shelters brought out extra cots and opened doors for people fearful of the deadly cold.

"You have to be inside the way it is now. If you're not, they'll find you stiff," said Elizabeth Austin, a homeless woman who sought warmth at an inner-city Birmingham church.

Multiple deaths have been blamed on this week's cold, including a 44-year-old man whose body was found face-down in the snow early Friday in Billings, Mont.

In Ohio, a winter storm warning was in effect until Saturday morning. That's on top of the snow that had already coated Interstate 70, where a tractor-trailer spun out of control Thursday, crossed the median and swerved into oncoming traffic, colliding with a small bus transporting adult disabled passengers, the Ohio Highway Patrol said.

Three passengers on the bus were killed, as was its driver. Six other passengers on the bus, which was carrying 11 people, were injured, as was the driver of the commercial truck, Sgt. Raymond Durant said.

Schools in at least 10 states were closed, as were many roads and government offices.

Travel was beginning to return to normal Friday at Chicago's airports, after a storm that dumped about 8 inches of snow. The Chicago Department of Aviation said there were still minor delays at O'Hare International Airport because crews had to deice aircraft before they could take off.

Some Nebraska cities were cut off because highways leading in and out of town were blocked or all but impassable.

Amtrak announced that its train between Chicago and Denver wouldn't operate Friday because of blowing and drifting snow in Nebraska.

Snowfall was heaviest in Minnesota and parts of South Dakota, where some drifts were too big for snowplow drivers to clear.

Nowhere was it colder than in Bismarck, N.D., where wind chills hit 52 below zero Thursday and the temperature reached 14 below. Wind chills were still near 50 below in the Dakotas on Friday.

While North Dakotans get plenty of practice bundling up, folks in other parts of the country were still learning the basics.

In Mobile, Ala., hit by a rare arctic chill on the coast, Salvation Army spokesman Stacey Killingsworth said shelters were "filled to the brim." One that normally holds up to 28 homeless men a night has been averaging 115 in recent days, she said.

"We don't turn anyone away, including women and children. We've used cots and mats. We've put people in the auditorium and hallways," she said.

In Florida's Panhandle, vapor was rising off the Gulf as warm water met the frigid air.

"It's so cold that sparrows that have crawled under the plastic on our heated deck don't want to leave," said Scooter Montgomery, manager of Peg Leg Pete's Oyster Bar on Pensacola Beach.