A Vermont Traffic Cam Proves The "Bridges Freeze Before Roads" Warnings

Northbound Interstate 89 Exit 10 in Waterbury,
Vermont this morning in this screen grab from a 
Vermont Agency of Transportation webcam. Note the
area of snow and ice ahead of the vehicle. That's
a bridge, showing how they DO freeze before the road.

As of early afternoon, road conditions had vastly improved in Vermont since this morning. 

The snow has stopped, and there were only a few patches of non-freezing drizzle left behind. Most places were a little above freezing as of 2 p.m. 

This morning, the worry was bridges and overpasses freezing even if roadways stayed fairly clear due to warm ground temperatures. 

That set up is especially dangerous, because speeding traffic encountering frozen pavement on bridges is a recipe for crashes.

There was a great illustration of the bridges freeze before road rule this morning on a Vermont Agency of Transportation webcam. It showed Interstate 89 northbound in Waterbury, including Exit 10 to Route 100.

The long exit ramp includes a bridge over Graves Brook. The screen grab in this post shows what the exit looked like during this morning's storm. Click on the image in this post to make it bigger and easier to see. 

As you can see, the Interstate, and most of the exit ramp looked just wet, maybe a little slushy.  But see that stripe of white in front of the vehicle taking the exit?  That's the bridge I was talking about. It was snow and ice covered, unlike the rest of the road.

The vehicle in the photo appeared to be braking, the motorist probably wisely anticipating the ice on the bridge. 

The bridges freeze before road rule will be with us all winter. But it's especially prevalent this time of year, when lingering warmth in the ground radiates to the road surface. There's no ground under bridges, obviously, so those overpasses get cold, quickly. 

Let this be a lesson: Don't let icy bridges surprise you this winter. Keep your speed steady and slow on approach to the bridge.  Don't smash your foot on the brake as soon as you are on the bridge.  You will probably spin out. Don't do any sharp accelerations or turn your steering wheel much. Just coast across to the other side.  

By the way, if a thermometer in your car says it's above freezing, don't necessarily trust it. It might be, say, 34 degrees. But it could well have been below freezing recently, and the bridge might not have had a chance to thaw out yet. 

All this is just a word to the wise, as it's just the start of winter.