WHY does bridges get icy???

Question

but not the roads.

Answer 1

they are made of metal and hold the cold more.

Answer 2

The freezing wind strikes the bridge above and below and on both sides, so it's losing heat from every side. The road is only losing heat from its surface.

Even while the temperature on the road surface is dropping, the heat underneath the road keeps it warm enough to prevent icing as temperatures in the atmosphere drop below freezing.

Bridges have no way to trap any heat, so they will continually lose heat and freeze shortly after temperatures in the atmosphere hit the freezing point.

Answer 3

as a truckdriver of 34 years the only one even close so far is UCANTCME, he's got it right, the ground stays warm longer and heats the road from the bottom where the bridges are in the open and stay at whatever the air temp is.

Answer 4

Because politicians vote themselves outrageous raises instead of spending the money on heating elements that go into the concrete which would save lives, property and all of us money on insurance!   Dont forget to VOTE!

Answer 5

Because the cold air circulates under the bridge, as well as on top of it, so it's getting frigid air from all sides, whereas the road is only getting cold air from the top.  That's why "Bridge Freezes Before Roadway."