Special Weather Statement issued December 24 at 5:38AM EST by NWS

…Areas of Black Ice possible this morning… Temperatures are near the freezing mark. Wet surfaces combined with these freezing temperatures, will lead to areas of black ice on untreated surfaces. Elevated roadways such as bridges and overpasses, highway on and off ramps, as well as sidewalks, driveways and parking lots will be most susceptible to black ice.

Source: National Weather Service Alerts for Vermont