The North Texas Tollway Authority began plowing toll roads with convoys Thursday night, using motor graders and truck-mounted plows to move snow and slush to the shoulder and applying deicer. That work will continue throughout Friday as staff work 12-hour shifts.

The National Weather Service said a tenth of an inch of ice could accumulate on raised surfaces, such as bridges, and some areas could get up to a quarter inch. But the main travel impacts are expected to be from sleet and snow.

Black ice is a thin layer that forms on surfaces such as roads, sidewalks and driveways when temperatures are 30 degrees or lower.