UPDATED 02/03/11 7:30 a.m.

HIGHLAND, Ind. (CBS) – The snow largely stopped in the city of Chicago by Wednesday afternoon, but the lake effect kept it falling in Northwest Indiana well afterward.

As CBS 2’s Susanna Song reports, by 5 a.m. Thursday, the snow was no longer falling in Indiana. But frozen snow was packed into the ground, and roads remained dangerously icy as the temperatures plunged.

Officials at the Lake County, Ind., Sheriff’s Office said they would reassess conditions later in the day, but for now, a state of emergency remains.

The main roads are generally safe to drive on, but many lesser roads remain dangerously slick.

The blizzard Tuesday and Wednesday left the on- and off-ramps on the Borman Expressway (Interstate 80/94) dangerously slick. Semi-trailer trucks jackknifed and became stuck.

Overnight, even though the roads were plowed, they remained glossed over with ice. Meanwhile, the frozen snow made it difficult to shovel or drive.

Lake County sheriff’s deputies advised motorists Wednesday night to refrain from driving as much as possible.

“The philosophy is to open the main arteries, and as far as doing the side streets next, we keep people more at home and off the roads for safety reasons,” said Lake County Sheriff John Buncich.

“The roads are passable now. All the main roads are pretty much passable. The secondary roads in the subdivisions still need some work, probably by week’s end,” said snow plow driver Mark Boykin.

Police also advise that motorists continue to stay off the entry and exit ramps on I-80/94, since some accidents were seen overnight.

State patrols said they have had a few accidents overnight, but for the most part, it has been fairly quiet.

The highest snow total in Indiana was in Highland, where a heaping 25 inches fell. A total of 20 inches fell in Schererville and Munster, 17.5 inches in Crown Point, 17 inches in Chesterton, 14.5 inches in Hammond, 13 inches in Lowell, and 9.3 inches in Valparaiso.