Black Ice
- Thread starter BlueOvalFitter
- Start date
It sucks. My car literally could not sit on the road. It just slid off slowly at 5mph or so (I was driving SLOW). I did the same thing on my own two feet, lol. It was wild. WAY slicker than a skating rink.
I think anyone living where it gets cold and deals with snow has had a run in with black ice at some point. I think of black ice as ice conditions that sneak up and surprise drivers.
Typical conditions here are when moisture condenses on the road surface (ie: frost conditions). This typically happens on bridge decks and over culverts where the cold ambient air gets on both sides of the road surfaces. For the driver, they've been driving on dry roads for some time, and may not know or realize these conditions have set up. On top of that, this type of ice is mostly transparent. Ever wonder why there are signs like "Bridges may be Icy"? This is why - it doesn't have to be precipitating or blowing snow to create these conditions.
We have several bridges and even a strech of freeway we've set up automatic deicing systems using potassium acetate to combat bridge icing. One location is the infamous 35W bridge that fell and its replacement as well - the nearby St. Anthony Falls on the Mississippi River adds enough moisture to the air that this issue pops up even when the rest of the system is fine...
It also can pop up on segments of roadway that are colder than others - often from shading by trees, or other obstructions. We analyze large buildings for their potential affects on our road network - shading at wrong time can add serious deicing headaches...
Another scenario we are familiar with here is when temperatures go below zero F, car exhaust can cause and create black ice conditions. Typical locations are anyplace cars stop and idle (like at stoplights) or places where folks are getting on the gas (like on ramps to the highway). Traffic jams are great at creating these conditions.
And yes, deicing works fine on black ice, subject to all the other limitations of the deicing chemicals and temperatures. There is a reason you may see the trucks out even when it isn't snowing - and this is often it. We do a lot of proactive pretreatment of bridge decks in anticipation of these types of conditions.
Typical conditions here are when moisture condenses on the road surface (ie: frost conditions). This typically happens on bridge decks and over culverts where the cold ambient air gets on both sides of the road surfaces. For the driver, they've been driving on dry roads for some time, and may not know or realize these conditions have set up. On top of that, this type of ice is mostly transparent. Ever wonder why there are signs like "Bridges may be Icy"? This is why - it doesn't have to be precipitating or blowing snow to create these conditions.
We have several bridges and even a strech of freeway we've set up automatic deicing systems using potassium acetate to combat bridge icing. One location is the infamous 35W bridge that fell and its replacement as well - the nearby St. Anthony Falls on the Mississippi River adds enough moisture to the air that this issue pops up even when the rest of the system is fine...
It also can pop up on segments of roadway that are colder than others - often from shading by trees, or other obstructions. We analyze large buildings for their potential affects on our road network - shading at wrong time can add serious deicing headaches...
Another scenario we are familiar with here is when temperatures go below zero F, car exhaust can cause and create black ice conditions. Typical locations are anyplace cars stop and idle (like at stoplights) or places where folks are getting on the gas (like on ramps to the highway). Traffic jams are great at creating these conditions.
And yes, deicing works fine on black ice, subject to all the other limitations of the deicing chemicals and temperatures. There is a reason you may see the trucks out even when it isn't snowing - and this is often it. We do a lot of proactive pretreatment of bridge decks in anticipation of these types of conditions.
you know what to if it's icy? Take the bus...
When I was 17 years old I had driven to Baton Rouge to visit my sister. It was just after Christmas and it was like 22*. Before I left from her house at about 1 AM my 69 F-100 drivers side door was frozen shut. After pouring water over it and into the seams it finally opened. My sister suggested I stay the night due to the roads being frozen, maybe.
As I was driving down a busy road (normally) the light began to turn red. When I applied the brakes my truck started sliding and spinning in circles. Luckily, there were no other vehicles on the road. When I finally stopped, I was facing in the direction I was driving from. Do you think it was black ice that I drove over?
As I was driving down a busy road (normally) the light began to turn red. When I applied the brakes my truck started sliding and spinning in circles. Luckily, there were no other vehicles on the road. When I finally stopped, I was facing in the direction I was driving from. Do you think it was black ice that I drove over?
probably was, BOF
Zee09
$200 Site Donor 2023
Here the bridges are the ones that get it. Very dangerous.
Same here in La.
Especially prevalent on Colorado passes on sections of highway where low winter sun never shines. Rabbit Ears comes to mind as one of the worst for black ice on the eastern side.
That's that "hard frozen" ice. The kind where if you got out of your car with a blowtorch (or Brenz-o-matic propane torch) it still wouldn't melt it, the density of the ice too great.
Only thing you can do, no matter what tire you have, AWD system, etc... Drive slow, let vehicle regain traction, let the momentum carry it how it will.. feather brakes, turn into the skid, etc.
Only thing you can do, no matter what tire you have, AWD system, etc... Drive slow, let vehicle regain traction, let the momentum carry it how it will.. feather brakes, turn into the skid, etc.
One thing I didn't see mentioned in skimming the thread, is don't use cruise control when ice is a possibility. Hitting ice with the cruise control engaged will get your attention, then it's a just a question of whether you can regain control before crashing.
Lol like its no big deal! Wonder if that bus was AWD?
I drove that road a lot for about 20 years, now not as often.
It's very steep and long through a mountain pass. It can be a white knuckle experience for many miles. You aren't allowed to stop anywhere due to avalanches.
In the summer there are lots of burned areas on the pavement from vehicle fires.
I got stuck from a land slide that covered the road, the alternate route took another 20 hours to get home.
Well, I've never come across an AWD city bus so doubt it. But I think they put winter tyres on it and the cars didn't have them
Buses are so very heavy they do well in snow.
I think one wheel weighs 100-150lbs.. I remember something like that. I think with the tire on it it weighs more.
around 80 kg wheel and tyre combined, so 180 popunds, ish... Used to mount them when I was a bus tech. We had some types of busses that had real trouble in snow though
That is a VERY dangerous job. I think they now have some sort of cage to stand within in case something with the tire/rim go awry.
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