The reason for bridges freezing first is really quite simple. Bridges are cooled from above and below. Adjacent roadways are cooled and lose heat from the one surface exposed to the freezing conditions. Bridges will cool to the freezing point quicker and if there is moisture on the surface that will freeze as well.
Drive with care this winter and to help with that here are a few more tips for driving in the snow.
Stay home. If you really don’t have to go out, don’t. Even if you can drive well in the snow, not everyone else can. Don’t tempt fate: If you don’t have somewhere you have to be, watch the snow from indoors.
Meteorologist Mike Morrison