From the National Weather Service:
Special Weather Statement National Weather Service Boston/Norton MA 243 PM EST Mon Feb 18 2019
...SOME SLIPPERY TRAVEL EXPECTED LATE AFTERNOON AND EVENING.... Light snow will be ending by late afternoon and early evening. Temperatures have dropped into the 20s across northeast MA. This colder air will overspread Rhode Island and southeast MA during the next few hours and Cape Cod by evening with temperatures falling below freezing. Any wet or slushy roads will turn to ice resulting in slippery travel on any untreated roads. Motorists should use caution if traveling through this evening.