Saturday, the Washington State Department of Transportation warned drivers to be cautious, as they expected black ice to form on roadways. “The one thing for travelers to be conscious of is the potential for anything that was wet to refreeze and become black ice. Watch out for overpasses that tend to freeze quicker, curves that could be slick tomorrow morning,” David Rasbach with WSDOT told KIRO 7. Rasbach said WSDOT crews were using anti-icer in the lowlands and would use de-icer as well.