An ill-timed dusting of snow combined with temperatures double digits below zero combined to create slick conditions on metro area roads Friday morning and spawn scores of crashes, rollovers and spinouts.

The mishaps began early and kept right on coming as traffic levels increased, with drivers on nearly every major highway feeling the effects.

MnDOT crews were out overnight after a light snow fell, said MnDOT spokeswoman Anne Meyer. But with temperatures at minus 13 degrees, chemicals don't work as well, she said. Heat created from the friction of tires melts the snow, but liquid refreezes instantly, forming icy spots commonly referred to as black ice. Vapor from exhaust also freezes on pavement as traffic slows down, she said.

"It's a domino effect," Meyer said. "Chemicals don't work as well with these temperatures. Once traffic picks up, we see the accidents."

It didn't look good for a pickup truck driver who spun out on the Cedar Avenue bridge over the Minnesota River in Eagan about 7 a.m. Friday. Passersby stopped to help the driver get out of the cab, which climbed a snowbank and the guardrail and was dangling precariously off the side of the bridge. Good Samaritans held down the back end of the truck to keep it steady as another pulled the driver to safety, Minnesota Department of Transportation cameras showed.

State troopers were put to their paces as they were radioed to call after call.

"We do our best to handle all crashes as they occur on the freeway, but always appreciate any assistance from [other] law enforcement agencies," said Lt. Gordon Shank of the State Patrol.

Shank said troopers prioritize crash response depending on location and injuries involved. For mishaps that don't involve injuries and result in only minor damage, drivers can move to the nearest exit or safe place to exchange information.

But many did need a trooper's presence. Among them was a multivehicle wreck about 8:45 a.m. that led to the closure of the ramp from northbound I-94 to westbound I-694 in Brooklyn Center. The ramp remained closed at 9:15 a.m.

Traffic stacked up on westbound Hwy. 10 in Anoka and Coon Rapids after a crash with injuries near 7th Avenue forced authorities to close the highway for a short time about 7 a.m. The road has since reopened.

Shank and Meyer both reminded drivers to slow down in treacherous conditions like Friday's, or if possible, "delay your trip," Meyer said.

Tim Harlow • 612-673-7768