That bridge freezing thing

No, seriously, why does it matter than the bridge freezes before the road surface? Certainly, there has to be a road expert in my readership.

Update: Lots of good explanations in the comments below. It all stems from my misreading of the sign (also explained below). In the meantime, here’s a good explanation. (Thanks, Adam!)


 
 
 

6 Responses to “That bridge freezing thing”

  1. Bart
    7. June 2005 at 08:20

    I’m no road expert, but I do live in a part of the country where during the winter the temperature kinda hovers around the low 30s, but doesn’t typically drop below it that often.

    Given those conditions, water on the road might not freeze, and driving conditions are all right. But if you come across a bridge, the road running across it might be icy. So if you’re driving at normal speeds and then unexepectedly hit an ice patch, you’re likely to lose control of your car.

  2. Odis
    7. June 2005 at 08:46

    There is no earth (directly) under a bridge. The earth can “hold” heat longer, so water on a bridge will freeze before water on a typical road surface with ground underneath.

  3. EarlLantern
    7. June 2005 at 10:37

    Exactly! If a person is driving on roads that are not covered with frozen precipitation, and that person drives onto a bridge that is covered with ice, that person might be inclined to drive as if there were no ice. And everyone knows that can lead to an accident.

    On the other hand, as evidenced by your query, not everyone knows that bridges freeze before non-bridges roadways. And even fewer know why. But, thanks to the second reply here, all the readers of this fine blog now know.

  4. rob
    7. June 2005 at 11:45

    Don’t listen to these people. It’s because of the trolls. Seriously. They’ve had it in for us for a while. Never trusted the guys.

  5. Augie De Blieck Jr.
    7. June 2005 at 13:00

    OK, so here’s what has always confused me about that sign: I was assuming they were referring to the roadway on the bridge’s surface. Does that make any sense? I thought it meant that the bridge, itself, would freeze before the macadam on top of it on which you drive.

    Now it makes more sense that the bridge’s road surface freezes before the road surface found on solid ground.

    Wow, the things you learn around here.

    Thanks, everyone, for clearing that up for me. Today, I am a better person.

  6. Adam
    7. June 2005 at 14:09

    I wuv google: http://travel.howstuffworks.com/question566.htm