State police Sgt. Paul Shavack said Wednesday the speed limit on Interstate 495 near Wilmington has been cut from 65 mph to 45 mph due to heavy snow.
He says there are numerous disabled and abandoned vehicles across New Castle County, and at least 25 vehicle crashes have been reported.
Conditions are better further south, with sleet in Kent County and rain and wind in Sussex County.
The National Weather Service says it will all change to snow by evening with overnight accumulations ranging from 1 to 3 inches in Sussex to 8 to 12 inches in the northern part of the state.