A tree is coated with ice as vehicles travel a slick Interstate 80 in Lincoln, Neb., Wednesday, Dec. 23, 2009. A major winter storm is promising to bring a white Christmas to much of the nation's midsection, though countless holiday travelers faced slick roads and scattered flight delays and cancellations Wednesday that only looked to get worse.(AP Photo/Nati Harnik)AP – Holiday travelers battled slick, icy roads and flight cancellations and delays on Wednesday as a major winter storm began to spread across much of the nation’s midsection — and the worst of the weather was still expected to come.