By Shereen Siewert Morning commuters should plan on additional time Monday as many roads remain snow-covered and slippery from the snow that fell on Sunday. Clear skies and plunging temperature are also resulting in patches of dense fog throughout the region, which will persist through mid-morning. Where fog is present, frost may deposit on previously treated roads, causing them to become slippery once again. As of 7:20 a.m. Monday, Hwy. 51 from Rothschild to Merrill, I-39 from Rothschild to Portage, and Hwy. 29 from Abbotsford to just west of Green Bay are ice covered, according to the Department of Transportation. For the latest road conditions, visit https://511wi.gov/ or call 511.