From the National Weather Service:
Special Weather Statement National Weather Service Boston/Norton MA 613 PM EST Wed Dec 11 2019 ...WATCH FOR ICY SPOTS INTO THE OVERNIGHT... Temperatures are expected to fall into the teens to lower 20s as colder air builds into the region. Any wet pavement or slushy snow on roads and sidewalks from today`s snow event will freeze, with untreated surfaces becoming slick. Motorists driving tonight into early Thursday morning should drive with extra caution. Pavement that looks wet may be icy.