Ice has started to form over North Texas roadways, and crashes are piling up in a way that’s reminiscent of massive wrecks that plagued North Texas during the last major winter storm. Now, an 18-wheeler in Irving has jackknifed on the highway in a serious crash.

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

Drivers in North Texas should be extremely careful Friday morning after the region was blasted with wintry precipitation and below-freezing temperatures overnight, according to the National Weather Service.