Skidding downhill on black ice: survival tactics

Forums › Transport (cars, bikes and boats) › Skidding downhill on black ice: survival tactics

1 | 2 | 3 | 4 | 5

17127 posts

Uber Geek

Lifetime subscriber

#1826210 20-Jul-2017 21:23

Are there any cars with OEM black ice detection? I would have thought it's fairly trivial to detect with 'intelligent' radar processing or something like that.

Batman

Mad Scientist
29763 posts

Uber Geek

Trusted

Lifetime subscriber

#1826218 20-Jul-2017 21:28

I'm no chemical engineer, but how to tell a piece of road that's -4C with no layer of frozen water aka frost vs 0C with a layer of frozen water aka ice? vs grit at -3C vs snow vs everything ...

Note you can have air temp at say 5C but still have ice ... you can ski on ski fields when the air temp is 5C for example ... and my snowman in the garden is still there (7C) a week after the snow.

mudguard

2119 posts

Uber Geek

#1826225 20-Jul-2017 21:33

gzt: Are there any cars with OEM black ice detection? I would have thought it's fairly trivial to detect with 'intelligent' radar processing or something like that.

I would say no. But it does 'look' funny, like frosty or reflective, problem is, even if it's 'visible' by the time you've noticed you're already on it.
I do like the blue cats eyes though. I drive most of the country every 30 days and the only place I've seen them is Motueka Valley Highway. Do they exist elsewhere?

alasta

6704 posts

Uber Geek

Trusted

Subscriber

#1826262 20-Jul-2017 22:37

My Kia had a warning indicator and chime that activated when the outside temperature is or has been below 4 degrees. Obviously that doesn't necessarily tell you whether there is going to be ice on the road, but it's a useful indication.

andrewNZ

2487 posts

Uber Geek
Inactive user

#1826269 20-Jul-2017 23:04

The flashing blue cats eyes are a pretty new thing, developed in 2012 for Dunedin originally. ODT article here
The ones in Otago are reportedly going to be removed due to reliability issues. ODT article here

They are all over the show now. I'm seeing more and more around workplaces.

No driver training is going to include a fairly localised trial product.

Batman

Mad Scientist
29763 posts

Uber Geek

Trusted

Lifetime subscriber

#1826272 20-Jul-2017 23:13

Reminds me of the glowing sword in LOTR

ANglEAUT

2322 posts

Uber Geek

Trusted

Lifetime subscriber

#1826289 21-Jul-2017 00:49

@tdgeek: ... best to allow it to roll if you have any small amount of grip to enforce that, rather than hit it head on.

@Sidestep & @Azzura, please educate me.: Why rather roll than hit it head on?

Please keep this GZ community vibrant by contributing in a constructive & respectful manner.

Samsung

Shop now on Samsung phones, tablets, TVs and more (affiliate link).

tdgeek

29746 posts

Uber Geek

Trusted

Lifetime subscriber

#1826318 21-Jul-2017 08:24

IcI:
@tdgeek: ... best to allow it to roll if you have any small amount of grip to enforce that, rather than hit it head on.

@Sidestep & @Azzura, please educate me.: Why rather roll than hit it head on?

My context was that you have slid on the ice, no control, and you're going to hit something hard and you are now near off the ice. If you lock the brakes, you have no control again so you will hit what momentum decides. If you allow the wheels to roll, there is some control for the little grip you have, now that you are off the ice and going into the ditch, so you have some ability to manage where you hit. Head on into a tree could be turned into a glance.

tdgeek

29746 posts

Uber Geek

Trusted

Lifetime subscriber

#1826319 21-Jul-2017 08:27

I keep it simple. Its below zero so there will be ice on the grass etc. It rained last night or late afternoon, so assume the already wet roads froze overnight

Sidestep

1013 posts

Uber Geek

Lifetime subscriber

#1826360 21-Jul-2017 09:34

IcI:
@tdgeek: ... best to allow it to roll if you have any small amount of grip to enforce that, rather than hit it head on.

@Sidestep & @Azzura, please educate me.: Why rather roll than hit it head on?

I didn't say I'd try to roll the car!

Looking Op's photo - in particular the tires on his 90's Prado - I don't think he had much of a chance of steering through it. I doubt I could've done much better. And as other have said - glad he's OK!
On a Canadian winter road you're fully expecting this type of thing to happen. On a NZ road it's more of a nasty surprise

In similar situations I've concentrated on crashing as safely as possible - not - rolling, but staying on the road if possible and trying to go in front first (cause airbags, crush zones, seatbelts all work best that way)
I'd rather smack into the bank on the uphill side of the road than fall off the cliff on the downhill side.

The problem is knowing when you've lost it and what's happening. Cause it happens fast.

I spent many Canadian winters beating my cars around frozen lakes & rivers, like giant skid pads - with & without stability/traction control - (while the father-in-law was ice fishing) and got better at telling when my cars would break loose, and recovering, and what exactly traction/stability does to help. (also having heaps of fun)

Turns out, with winter tires, solid frozen ice - at say 20 or 30° below is pretty grippy, 'just' frozen ice is by far the worst.
When drizzling rain first starts to freeze on the road is way more dangerous than a nice solidly frozen road. A nice crispy snow covered road is safer that a partially melted -or refreezing - slushy one.

Azzura

603 posts

Ultimate Geek

ID Verified

#1826382 21-Jul-2017 10:10

Like tdgeek says...
if your wheels are rolling then there is some kinda grip there. Before ABS, pumping the breaks is what you did (its hard to come over the natural instinct --- push the break harder when nothing is happening) --because a locked tire continues on in the direction the momentum was taking you...no mater where the locked skidding tire is pointing. I wouldn't be trying to gear down on black ice....you'd just break any grip you had.

Not sure barrel rolling the car is what I would be trying to do. How did you get rolling the car over?

I think, if we were living down on the south island in possible snow country and knowing (wife and I) what we know about snow/icy roads. We'd have some form of snow/ice capable tires on (for the season), that are good below 7C and above (our lives are worth it). And that is on all 4 wheels the same tires. Not just the front only...

Back home ---We use to go out in the car or a buds 4wd during snowstorms 30 to 40cms just for the fun of it (kinda miss it). Lets see if we can make it up this unploughed hill with snow drifts. doing donuts in parking lots.... During freezing rain storms (if you could get in your car), we'd still go out in the car (not doing donuts). If you had good tires you'd be alright drive accordingly (unless it was realllllyyyyy bad out!).

Rikkitic

Awrrr
18660 posts

Uber Geek

Lifetime subscriber

#1826386 21-Jul-2017 10:18

Not sure about modern cars but back in the 60s conventional wisdom said that a roll-over was preferable to a head-on. Having been in a few myself, I would tend to agree with that.

Plesse igmore amd axxept applogies in adbance fir anu typos

Greendrake

86 posts

Master Geek

#1826389 21-Jul-2017 10:32

Azzura:

How did you get rolling the car over?

There was a rocky ditch on the left side of the road, and the side itself was going down roughly 5-7 degrees. Because the road was bending to the right and the car kept skidding straight-left, the left front wheel went down the ditch and that caused rolling over.

Sidestep

1013 posts

Uber Geek

Lifetime subscriber

#1826403 21-Jul-2017 11:05

Rikkitic:

Not sure about modern cars but back in the 60s conventional wisdom said that a roll-over was preferable to a head-on. Having been in a few myself, I would tend to agree with that.

Cars were very different in the 60's. And a slow speed rollover's very different to a high speed one.

Since then 3 point self-tensioning locking seatbelts, collapsible steering columns, sheerable pedal mounts, deformable drivetrains with intrusion resistant floor panels, firewalls, padded dashboards, anti-whiplash headrests, changes in the way A & B pillars deform, door latch improvements and anti intrusion beams have been introduced.
In particular - crumple zones have a much greater depth at the front of cars, and strengthened occupant "safety cells" with multi position airbags are designed for protection in the majority of (front on) crashes, meaning deliberately rolling your car to avoid a head on crash is a bad idea.

Edit: Most modern cars' computers will do their best to keep you tracking forward and prevent you rolling anyway..

Fred99

13684 posts

Uber Geek

#1826418 21-Jul-2017 11:20

mudguard:
gzt: Are there any cars with OEM black ice detection? I would have thought it's fairly trivial to detect with 'intelligent' radar processing or something like that.

I would say no. But it does 'look' funny, like frosty or reflective, problem is, even if it's 'visible' by the time you've noticed you're already on it.
I do like the blue cats eyes though. I drive most of the country every 30 days and the only place I've seen them is Motueka Valley Highway. Do they exist elsewhere?

I used to drive a lot around the SI, often at night, over the Lewis or Arthurs Pass etc. Caution obviously needed - sometimes you'd see a slight sparkly reflection from the road ahead giving you enough warning to ease off and ready yourself for near zero traction coming up. Not that this is guaranteed to save you, but it's potentially a panic inducing situation when you hit ice unexpectedly - and panic reaction on the brakes or steering wheel are going to make it worse.

One thing which possibly helped was that compared to today, tyres weren't very good on wet roads. So, especially if driving in a more "spirited" way in the wet, loss of traction and how to deal with it was more or less an essential skill. Not so much these days - apart from ABS and ESC doing some of the work for you, tyres are incredibly improved for wet grip.

1 | 2 | 3 | 4 | 5