WINSTON-SALEM, N.C. Tue Feb 24, 2015 2:57pm GMT

Commuters across the South faced dicey driving conditions on Tuesday as snow and ice blanketed roads, a wintry mix that turned some highways into parking lots and caused schools to close even after buses were already picking up students.

In North Carolina, crews were out salting roads but transportation officials warned that car crashes were increasing as the morning snow began to freeze.

"Conditions are slick," said Mark Mueller, a spokesman for the state's transportation department. "The storm honestly just moved in quicker than anybody expected."

Public schools and colleges closed or opened on delayed schedules. In Durham, North Carolina, some school children who had boarded buses were returned back home after school officials announced a delayed start and then complete closure for the day.

Winter weather advisories were in effect across the region, where another round of wintry precipitation was expected to arrive on Wednesday.

Crews in northern Georgia and the Atlanta area worked overnight to treat roads ahead of the snow, sleet and rain that hit the area on Tuesday, said Natalie Dale, a spokeswoman for the Georgia Department of Transportation.

Atlanta roads did not prove too troublesome for drivers as the wintry mix turned to rain, Dale said.

But she said in northern Georgia traffic accidents were causing slowdowns "because we have slush kicking up on the roads there."

"Some drivers seem to be overconfident when they should be taking it slow," Dale said.

Ice also caused problems in New York City on Tuesday, where ice halted the East River Ferry during the morning commute to Manhattan from some of Brooklyn’s trendiest neighborhoods, the ferry service said on Twitter.

The latest winter storm follows an ice storm that battered parts of Texas on Monday, cutting off power to thousands of homes and resulting in hundreds of traffic accidents and more than 1,500 airline flight cancellations.