WAKE COUNTY, N.C. — Black ice caused hazardous driving conditions -- especially along bridges and overpasses -- throughout the Triangle Friday morning.

The Highway Patrol said 170 separate wrecks were reported in Durham, Johnston and Wake counties just between 6:30 a.m. and 9:30 am.

Most were single-vehicle wrecks, where vehicles slid into guard rails.

One fatality in Orange County was reported by the Highway Patrol. Authorities said Alice Helen Pratt was driving on Pleasant Green Road when she was sideswiped by another car.

Pratt died in the accident. Authorities have not released the name of the other driver, who was injured. That person may be charged in the incident. No other life-threatening injuries were reported in the area.

A number of wrecks were reported along Interstate 540, where traffic was backed up for about 3 miles.

At one point in the morning, the ramp at I-40 and I-540 in Durham County was been closed after a tractor-trailer jackknifed on the overpass.

In Johnston County, a woman and her infant daughter were helped by a passerby after their

SUV slid off Barber Mill Road and into a creek

.

The state Department of Transportation was out early Friday treating major roadways.