Snow Madness

[Tithera]

Ok, so we just a combination of freezing rain (at the beginning of the week) and snow (started yesterday round 1pm and continued through this morning, on top of the snow we had last week) and the roads are, well, shit. Makes for exciting commutes. (not!)

Are you serious?
A pick-up, which was rear wheel drive and did not have 4x4 was barreling down the not-yet-plowed road much faster than was safe. I was happy to continue doing my 20mph cruise. Not risking my life like that!

Let's go ice skating!
We got the freezing rain on Tuesday night and a little in the morning. I went to doc's appointment early in the morning and was having one hell of a time keeping control of my car. After my appt. I was heading to class when I got to a main road. I attempted to stop for a light when my car started skidding. I did the normal pump the brakes thing, but I couldn't get any traction whatsoever. I ended up slightly sideways on the curb. Thankfully, that stopped me cause if I had gone any farther, I would have side swiped/rear ended a brand new 2011 Mustang. A car behind me then hit the ice, did a 180 spin and soon as it gained traction, went the opposite direction to get out of the way. Car behind that skidded slightly, but thankfully did not hit me. That scared the crap out of me enough that I turned around and went home. I wasn't even going to TRY and make it to the other side of town with the roads that bad. My professors were nice about it though and said it wouldn't count against me. Car came away without a scratch.

fuck!
Had a painful brain fart earlier this evening. It is 1 degree out, (below 0 with wind chill). My car had been sitting since yesterday since I had no where to go. I was on my way to the gas station and my car was driving weird. At first I thought my tire was going flat. But when I pulled up to the station, all the tires were fine. A build up of slush and snow from the previous day was actually interfering with my front tires (it being a front wheel drive car). So I automatically kick the slush hard to get it off, forgetting that fact that it had stayed in the teens and less all day and night. Yep, it was frozen solid, and I kicked it with my toes as hard as I could. I do believe my big toe is now broken. But, nothing I can't handle. I'm a fast healer and have broken this toe multiple times before because of soccer, so I know how to walk without putting pressure on it. Hurts like a bitch though!

[EvilEmpryss]

I'm glad you made it home safely through all of that. One thing concerns me, though: does your car have antilock brakes? If it does, then you were doing the wrong thing by pumping the brakes when it started to slide. Antilock brakes do that automatically. Pumping them interferes with this action and can make your slide worse. Just put steady pressure on the pedal and let the car do the work.

[fma_fanatic]

I've got a few to add

SUVs/MUVs/Any oversized truck

Hey guys, I realize that I'm taking my time because the county can't be bothered to get off their collective asses and plow the roads. However, this doesn't mean that you should go blasting around me or tailgate me to go faster.

This also goes for the other cars. I'm sure you feel comfortable speeding along the roads, but see that nearly jackknifed truck? Yeah..I'm going to avoid that thank you.

[Chromatix]

Anti-lock brakes are great, but some road conditions, including sevre winter conditions, can defeat/confuse them. In those cases, it's better to pump the brakes rather than rely on something that clearly isn't working.

In snow, maximum traction is in fact achieved with skidding wheels. What you lose however is control. A technique I've seen local bus drivers use in blizzard conditions, is to keep braking in a straight line, then make a sharp turn at very low speed, rather than the wider turn that would be appropriate in dry conditions. This works because that type of bus has two rear axles, and therefore naturally stays straight when it loses traction on all of them.

On ice, there is pretty much nothing you can do for traction, and anti-lock brakes are usually not subtle enough to get what little you can. All you can do is try to avoid spinning, which requires wheels turning normally while you are still pointing roughly ahead. Any braking you get in that situation is a bonus. Incidentally, if only one side of the car is on ice, you *will* lose control if you brake hard enough for ABS to activate.

On dry or ordinary wet roads, assuming you are not aquaplaning(!), there is still enough traction for normal braking, and ABS only kicks in when you exceed what the road is capable of giving you. This is fine, just hold the brake in steadily.

Incidentally, I infer from posts on here that many American cars still don't have ABS. What is this, the third world?

[blas]

I have traction control, not sure if that's the same as ABS.

I still drive as if I don't have it. It doesn't matter, once it starts snowing, every intersection, the annoying little "!" shows up on my dash and the warning LOW TRACTION comes on. I am so sick of seeing that.

[Kogarashi]

Incidentally, I infer from posts on here that many American cars still don't have ABS. What is this, the third world?

I think part of it depends on the age of the vehicle, and it may be an option rather than standard on many cars. I know our own jeep ('95) has it, but it's the kind that feels like the car's shaking itself apart rather than gentle pumping. It scares me every time it kicks in when I'm not expecting it (such as on dry roads when I brake just as I hit a shallow pothole), and the other day it caused me to lose control enough that I didn't bother with it afterward and just pumped the brakes gently to slow down, which worked worlds better. I liked the ABS in my parents' minivan ('96) better, which felt like gentle pumping when it engaged and didn't seem to cause near as much control loss.

[protege]

I think part of it depends on the age of the vehicle, and it may be an option rather than standard on many cars. I know our own jeep ('95) has it, but it's the kind that feels like the car's shaking itself apart rather than gentle pumping. It scares me every time it kicks in when I'm not expecting it (such as on dry roads when I brake just as I hit a shallow pothole),

That's why it's optional on some vehicles. Some drivers, myself included, don't like it. Several cars I've borrowed, had systems that did exactly what you described. I've actually felt *less* safe in those cars. Also, even with ABS, you can still slide on loose gravel (and ice) even if you're applying constant pressure. None of my own cars have come with ABS, even the current Corolla. What can I say, other than when I started driving, ABS wasn't common...so I never had to deal with it. I guess I really never learned to "depend" on it, so I didn't miss it. Instead, I learned how to stop without locking the brakes up...either by downshifting (and letting the car's weight slow me down), or by gently pumping the pedal.

[Tithera]

No, my car does not have ABS, it being a '90 Honda Hatch. I don't really like ABS any way. My moms Kia Rondo has it and it's sensitive as shit. We were driving north to visit my grandma round christmas time and it was snowing. Every single time my mom even tapped the brakes, ABS would activate and it would jerk until it came to a complete stop. Didn't help in sliding matters either.

[Chromatix]

I have traction control, not sure if that's the same as ABS.

It isn't. Traction control is for applying power, ABS is for braking.

But I'd be extremely surprised if a car with traction control didn't also have ABS.

[blas]

Usually cars with ABS say so somewhere on the steering column or by the dash. I don't see ABS. I better go get the owner's manual.

What irritates me, whenever it's raining/sleeting (or especially when I am just leaving the car wash) is when I apply the brakes, the brakes go THUD THUD THUD THUD THUD THUD and it's as if I'm slamming the brakes when I'm merely tapping them.

[Chromatix]

That's typical ABS behaviour. It repeatedly releases and applies the brakes when it thinks the wheels are losing traction under braking, in an attempt to keep them turning and thus give you some steering control. The way it does this is to pulse the hydraulic amplifier system which sits between the brake pedal and the actual brakes, so you feel it acting through the pedal.

On a dry road, keeping the wheels turning also stops the rubber melting on the bottom of the wheel, and thus improves your stopping distance under emergency conditions, but this doesn't really apply to winter conditions. It does explain why you sometimes see intermittent black stripes on the road...

Where ABS goes wrong is that it only has an indirect idea of how fast the car is moving, via the speed of the wheels. This is why it often gets confused on gravel and ice and becomes ineffective.

Some trains have a system which is very like ABS and/or traction control, but operates in conjunction with a doppler radar unit which measures how fast the train is really going (essentially, a speed gun pointed at the trackbed). While relatively complex and expensive, it's a definite plus for heavy freight operators. Most passenger trains now have anti-slip and anti-slide mechanisms but without the radar, and thus with the same limitations as ABS.

[Mytical]

I'll repeat what I've said many a time. As temperatures drop, it seems like IQ drops. Maybe it is some prehistoric automatic response..or whatever, but people seem to get even more idiotic when usual when snow/ice is on the road.

ABS, 4WD, whatever you have it comes down to one thing. Knowing what you and your vehicle are capable of, and being smart about driving on snow/ice.

[Daemonmonkey]

Where ABS goes wrong is that it only has an indirect idea of how fast the car is moving, via the speed of the wheels. This is why it often gets confused on gravel and ice and becomes ineffective.

I will have to say against you in this matter. I live in a country where winter conditions exist from October to March and we have seen that ABS indeed helps by both reducing speed and avoiding collisions due to the ability to steer away.

Tests have been made several times by professional drivers, like rally-drivers, with cars with and without ABS. The result has always been advantage for ABS (they have used both "pedal to the floor" and pumping techniques in cars without ABS).

Why many people fail with ABS is because they get scared of the pumping effect you feel on the pedal. That's why we train driving in slippery conditions.

Some trains have a system which is very like ABS and/or traction control, but operates in conjunction with a doppler radar unit which measures how fast the train is really going (essentially, a speed gun pointed at the trackbed). While relatively complex and expensive, it's a definite plus for heavy freight operators. Most passenger trains now have anti-slip and anti-slide mechanisms but without the radar, and thus with the same limitations as ABS.

Most newer electric trains have magnetic brakes, it works without making physical contact with the rails. See Linear eddy current brake (Wikipedia)

Of course this means that petrol-driven trains need to have a generator to create the current needed for this, thus making it unprofitable.

[Chromatix]

Hmm, I've never seen a petrol-driven locomotive larger than "light shunter" size. Diesel ones, yes.

Worldwide, most diesel locomotives have a big generator or alternator in them already, but for some reason the eddy-current brake is still not very common. Possibly it has a tendency to interfere with signallng equipment.

[Daemonmonkey]

Hmm, I've never seen a petrol-driven locomotive larger than "light shunter" size. Diesel ones, yes.

I was trying to summarize all fuel-driven locomotives... (also English is not my native language...)

Worldwide, most diesel locomotives have a big generator or alternator in them already, but for some reason the eddy-current brake is still not very common. Possibly it has a tendency to interfere with signaling equipment.

I believe that most locomotives use the diesel engine to power the hydraulics, rather than using electric drive system.

The eddy-current brakes are made so not to interfere with signaling equipment, and often is used as a supplement, like emergency braking.