skidding on black ice

[Looking4new]

ABS works good on my 5 axle semi trailer. I wonder how good it will be on my new set of B trains.

 

[Diamondpilot]

I agree, 99.9% of the time the ABS will do better in ANY condition.

Correct. Any other thinking is just plain wrong!

Chris

 

[Dr_Zinj]

It doesn't matter if it's black ice, glaze, refrozen runoff, hard pack, etc.; you're moving, and you've lost traction.

(1) Take your foot off the accelerator. It's not going to do you any good, regardless of whether you're driving a rear wheel, front wheel, 4 wheel, or all wheel vehicle.
(2) Steer in the direction of the skid. The idea is to get the steering tires rotating at the same speed the vehicle is moving at. That gives the tires the greatest contact time with any one piece of the surface and allows you to regain partial traction, even on ice.
(3) Evaluate your surroundings, fast. If you don't know your options, you can't make decisions.
(4) Prioritize your collision options. Driving off a cliff is the probably the worst thing, and shouldn't be chosen under nearly any circumstance. Striking a fixed, immovable object is the worst thing you can chose to do. (Concrete bridge abutments, trees, boulders, etc. Front ending a vehicle heading toward you is second. Glancing blow approaching each other, rear ending one, striking a moveable object, or possibly going into a lake or river are third. Glancing blow in passing is fourth. Running off into a field of snow is fifth. If people are what you're going to hit, then hit anything else but the people. And if you can't avoid them, hit as few as possible.
(5) Pray.

The best thing to do is practice doing deliberate skids and spins and recoveries in an empty lot with no curbs or things to run into. Play "What if" while driving. Plan ahead for what you would do under various circumstances. Make sure you have insurance, and your insurance card in the car. Cell phone or CB if you still have one.

 

[corl]

I have always enjoyed finding my cars limits on a snow covered parking lot. Knowing your car and experiencing sliding to the point of relative comfort (not white knuckled grip on the steering wheel) will provide the best insurance. I raced SCCA for a number of years and experienced dry and wet weather loss of traction at higher speeds. It is a learned experience. Hard to correct if you have never experienced it before. If you are going to hit something it is best to hit it backwards and lean hard into the backrest and headrest just before you hit. If you go into something forward remember to take your hands off the steering wheel just before you hit - can save a broken wrist etc. I always had my best races in the wet as I passed other competitors that had spun off course. Did slide off course into the snow once at VIR during practice.

 

[MattLynch]

ABS does not stop faster, it simply allows the driver to maintain control during a panic stop. In fact non ABS brakes will stop faster in snow and gravel due to the snow/gravel piling up in front of the skidding tyres.

 

[zzvyb6]

ABS does not stop faster, it simply allows the driver to maintain control during a panic stop. In fact non ABS brakes will stop faster in snow and gravel due to the snow/gravel piling up in front of the skidding tyres.

Wrong again. Snow buildup lubricates the tire interface with water (snow under a loaded tire is usually melted and refreezes as it exits. This phenom is what causes black ice to form. Its refrozen water. Gravel is the same as running over ball bearings. A rolling tire has the greatest traction (Mu coefficient of friction). The peak friction coefficient is achieved at only a few percent of slip. It takes wheel slip sensors, electronics and fast hydraulics to run this feedback control system at a frequency sufficient to improve stopping distance. Traction controls are just the same as ABS under acceleration. I suppose you believe your 0-60 times are better with traction control off, too. Measurements show its obviously otherwise. An electronically controlled automatic transmission with traction control will outdo your manual attempts, too. (I'm not talking about throttle intervention which kills fuel). The new systems know engine peak torque rpms based on transmission peak load rpms. This is also used to estimate the current weight of the vehicle for brake proportioning adjustments, which further decreases stopping distance under braking.

That ain't your grandfather's Buick...

 

[zzvyb6]

BTW: I once had to prove to a non-engineering designer that adding a lot of toe-in on a 4wheel steer vehicle stopped longer that one with standard settings. He claimed that the 'snow plowing effect' of adding toe-in (or out) improved stopping distance. It was 25% worse. (No he didn't get the patent awarded). But you can imagine the theories that abound, especially from people who take Oprah or Dr. Oz too seriously.

 

[jel1988]

Over the last little while I have weathered two ice storms in SC, my recommendation is to stay off the roads. The last ice storm the local new was interviewing drivers, the first was a lady she stated when she felt her vehicle start to slide she put them brakes right to the floor, they panned over to her SUV laying on its side. The second driver stated he had 4 wheel drive on his Jeep and that ice wasn't going to slow him down (neither would his brakes). The news casters gave their bit by telling everyone to steer into the skid yadda yadda yadda, not one of them suggested to slow down or stay home as SCDOT just doesn't have enough salters, briners to cover 1% of roads in the area if fact they couldn't even keep the Ravenel bridge in Charleston open with all of their equipment. When there is ice on the roads where people have little to no experience with it, if you value your life stay put.

 

[aczlan]

When there is ice on the roads where people have little to no experience with it, if you value your life stay put.

Yep. Even if you can drive in it, the idiots around you cant and they will hit you when they lose control.

Aaron Z

 

[MattLynch]

Lol, this is a well known fact and is taught in an introduction to abs course.