From Longman Dictionary of Contemporary Englishice over/up (also be iced over/up) phrasal verbLIQUIDto become covered with ice → icy Schools were closed when the roads iced over. The plane’s engines had iced up. → ice→ See Verb table
Examples from the Corpus
ice over/up• Schools are closed, roads are iced over, rain has turned to sleet.• Parts of the Bristol Avon were iced over, resulting in the cancellation of the Bradford-On-Avon Open.• The roads may have iced over, the rain may be too ugly to face. 