Triangle motorists again were caught off-guard Saturday afternoon as light freezing rain and a few pockets of sleet left a thin glaze of ice on some roads that the Highway Patrol blamed for at least 329 calls for assistance.

It wasn't clear how many of those calls involved accidents, however, and most wrecks were fender-benders, said state Highway Patrol spokesman Sgt. Everett Clendenin. No weather-related deaths were reported by evening, he said.

Most slippery spots were on bridges and overpasses. The Highway Patrol said the areas most affected in Wake County were Interstate 40 near Wade Avenue, U.S. 401 at the Neuse River and U.S. 64 at the Neuse.

To the west, police and the state Highway Patrol reported dozens of accidents on area highways, notably on the Durham Freeway and Interstate 540. Many on-ramps spawned accidents because, like bridges, ice forms easily on them.

Saturday night, streets in downtown Durham resembled ice rinks, but traffic was light, police said.

A winter weather advisory expired at 10 p.m. as the daylong round of light precipitation ended. Snow flurries were possible overnight but little accumulation was expected. "By [this] morning, everything should be done in North Carolina," said Mike Strickler, a hydrometeorologist with the National Weather Service.

Most of the wrecks took their victims by surprise.

"It looked like just rain," David Eby, a Durham firefighter, said Saturday afternoon at an accident scene on an overpass at the junction of Interstate 40 and I-540. "Then, bam, you got multiple wrecks all over the place."

Just west of Eby, five wrecks sat on an I-40 bridge. All five had slid out of control and careened off the road. All had done so at virtually the same time, on the same icy patch of overpass, Eby said.

In an instant, the bridge became a chaotic scene: hazard lights blinking and sirens blaring; flares directing the crawling traffic into center lanes, and emergency workers helping the driver of a black Ford Excursion into an ambulance.

According to the National Weather Service, temperatures in the upper 20s -- and a cold surface temperature caused by this week's sustained wintry weather -- were responsible for turning the light rain Saturday into a slippery mess.

Yet the weather spared large swaths of the Triangle. Orange County officials said they experienced no weather-related accidents. Crews in Raleigh reported virtually no ice on city streets.

At the Cameron Village shopping center in Raleigh, parking lots bustled and intersections were nearly as congested as on a regular Saturday afternoon. Steve Smith, who lives nearby, was at Eckerd's to buy a windshield scraper for his van. But Smith said the weather was doing nothing to upend his routine. "It's not affecting me at all," he said.

Little ice accumulated, and power companies reported no storm-related outages. No delays were reported at Raleigh-Durham International Airport, and transit systems were running on schedule.

Forecasters predict minimal accumulations for overnight and today. But after last week's surprise storm, city and state crews were taking no chances. They dispatched sand and tow trucks to the region's major highways -- many of which had been pre-treated Friday night with a salt-water mix. In Durham, they closed some overpasses until sheets of ice could be broken up.

And then they waited -- to see what the night would bring. Elwood Davis, Raleigh's streets superintendent, said, "An accurate weather forecast would really knock my socks off right now." Staff writer Samiha Khanna contributed to this report.