everything you ever wanted to know about black ice
11-13-10 | 11:52 PM
#1
everything you ever wanted to know about black ice
This is a very cool page:
https://www.atmos.washington.edu/~cliff/Roadway3.html
Icing on roadways is probably the most serious meteorological hazard faced by Washington State citizens and causes hundreds of serious injuries and several deaths a year. Sometimes called "black ice" when not clearly evident at night, roadway ice is not black at all, but is made up of frozen water that sparkles or is white when illuminated. This tutorial will describe a variety of weather conditions that can result in roadway icing and how one can determine when roadway icing is a threat. Some important meteorological principles that control surface icing will be reviewed as well.
11-14-10 | 12:40 AM
#2
Senior Member
Joined: Jan 2010
Posts: 7,037
Likes: 12
From: Eugene, Oregon
Thanks for the link. I rarely drive (once a year or less), but I have to drive over Santiam Pass this Wednesday to take a disabled friend to a medical appointment. Ugh, just in time for the snow/ice season in that area. Lucky for me, we only get ice in the southern Willamette valley once every few years. Since I am a real weather wimp, I just walk when the frozen stuff hangs around.
11-14-10 | 07:25 AM
#3
Charlotte, NC Commuter
Joined: Nov 2007
Posts: 190
Likes: 0
From: Charlotte, NC
Bikes: Gary Fisher Wahoo with Mammoth wheels
I looked at the article below the other day when preparing for possible riding in black ice and found it useful. Thanks for sharing this.
https://www.icebike.org/Articles/TechniquesBlackIce.htm
Ride safe,
Jeff
https://www.icebike.org/Articles/TechniquesBlackIce.htm
Ride safe,
Jeff
11-14-10 | 04:16 PM
#4
He's also got a blog entry w/ cool graphics describing low altitude (<2m) temp inversions that give icing on non-freezing (ostensibly) days:
https://cliffmass.blogspot.com/2010/1...your-life.html
https://cliffmass.blogspot.com/2010/1...your-life.html
11-14-10 | 05:33 PM
#6
Senior Member
Joined: Oct 2007
Posts: 1,522
Likes: 0
From: Madison, WI
Black ice doesn't actually sparkle when illuminated. That's the problem. It doesn't look wet, even in glaringly bright sunlight. At worst, the road surface looks clean. That's your tip-off, since the ground has to be very cold in order to get water to freeze so invisibly... so odds are there was a road salt layer everywhere. If it looks like the roads are pristine all of a sudden, get really suspicious. The change can happen very fast, even at a walking pace.
Glare ice is the same sort of icy glaze, but it is shiny and sparkly. This is much easier to see, and since you can see it you can take action. Glare ice can form in a wide variety of ways, and often melts easily. Melting is bad, since then the ice gets much more slippery. There is no way you'd miss glare ice when walking, even in cloudy weather.
People in climates where icing is rare won't often make a distinction between the two, since the end result tends to be the same.
Glare ice is the same sort of icy glaze, but it is shiny and sparkly. This is much easier to see, and since you can see it you can take action. Glare ice can form in a wide variety of ways, and often melts easily. Melting is bad, since then the ice gets much more slippery. There is no way you'd miss glare ice when walking, even in cloudy weather.
People in climates where icing is rare won't often make a distinction between the two, since the end result tends to be the same.
11-14-10 | 06:01 PM
#7
Bike ≠ Car ≠ Ped.
Joined: Jul 2007
Posts: 13,863
Likes: 6
From: Washington, DC
Bikes: Some bikes. Hell, they're all the same, ain't they?
Black ice doesn't actually sparkle when illuminated. That's the problem. It doesn't look wet, even in glaringly bright sunlight. At worst, the road surface looks clean. That's your tip-off, since the ground has to be very cold in order to get water to freeze so invisibly... so odds are there was a road salt layer everywhere. If it looks like the roads are pristine all of a sudden, get really suspicious. The change can happen very fast, even at a walking pace.
Of course, it helps to invest in winter tires, too; "all-season" tires are only half-optimal in all seasons. I didn't get studded tires, though..
11-14-10 | 10:52 PM
#8
Junior Member
Joined: Oct 2010
Posts: 123
Likes: 0
From: Redmond WA
I wish he had made that post one week earlier! On Wednesday AM, same day that likely inspired him to write that blog, I turned off the bike trail I was on to cross a wooden bridge and fell down faster than I thought possible, right on my knee. I slipped again standing up; the whole bridge surface was slick ice despite the 38 degree air temp. Thankfully I didn't break anything but will have to take a couple weeks off while the bruises go away 
11-18-10 | 03:33 PM
#13
Junior Member
Joined: Oct 2010
Posts: 6
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From: Montana
Bikes: 09 Surly Crosscheck commuter. Need a new bike for springtime rides...
11-18-10 | 07:23 PM
#14
Bike ≠ Car ≠ Ped.
Joined: Jul 2007
Posts: 13,863
Likes: 6
From: Washington, DC
Bikes: Some bikes. Hell, they're all the same, ain't they?
11-18-10 | 08:05 PM
#15
cyclepath
Joined: Sep 2005
Posts: 3,550
Likes: 1
From: "The Last Best Place"
Bikes: 2005 Trek Pilot 5.0, 2001 Specialized Sirrus Pro, Kona Lava Dome, Raleigh hardtail converted to commuter, 87 Takara steel road bike, 2008 Trek Soho
11-20-10 | 02:19 AM
#17
xtrajack
Joined: Aug 2008
Posts: 2,058
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From: Maine
Bikes: Kona fire mountain/xtracycle,Univega landrover fs,Nishiki custom sport Ross professional super gran tour Schwinn Mesa (future Xtracycle donor bike)
Studded tires don't help much with that. Last winter, I went down 4 times on the same commute on that stuff, after the last time, I walked the rest of the way home, pushing my bike.
