Traction control may have assisted this event, but enough to avoid it?
"a friend of mine crashed when she had to swerve onto some wet railroad tracks to avoid a car. As she described it the engine revved, the rear wheel spun, and she went sideways and high sided." By that description I'd assume this was multi lane traffic over a set of tracks that angled across the road.
I am a strong advocate that the rider must assess ALL aspects of the riding environment to avoid reactionary measures. Sure, its really easy for me to asses this at my desk. But factors like wet road/railroad tracks/traffic interaction sounds like many clues to be ready and to avoid close proximity to a car before entering the area. All relates to effective scanning/searching before getting there.
Tracion control is a good assist system, but the best "system" is and always will be between the rider's ears. Traction control starts in the brain and works at the eyes, hands and feet of the rider. Hope she's up and riding again!
Traction control allows for sloppy work at the controls. I'm not saying that it might not prevent some crashes, but my basic feeling is that it is just one more electronic gizmo separating me from the machine. I too drove a bunch of Subarus, but I learned how to make them slide and the one that came with ABS got its fuse pulled because I could stop faster using the transmissin and brakes together to make sure I never locked up more than two wheels at a time. They were also all manual gear boxes which does make a difference.
In regards to the Sequoia comment, Toyota traction control and ABS is overzealous in my 2008 Prius as well. Without snow tires, it flat out won't get out of its own way in the snow because the traction control won't allow any spin.
Because so much of bike control comes from factors beyond the computers control, I think the number of accidents which can be prevented through ABS and TC is limited relative to what can be done with four wheels. The computers can basically take over brake and throttle control. In a car, controlling four wheels independently, steering angle is the ony thing the car isn't taking over. On a bike, that isn't the case, and how you turn the bike changes relative to speed. Traction control and ABS may assist a rider is certain situations, but they can't save the rider from him / herself.
That said, learning how to control a bike in the dirt is some of the best training for how to handle situations on the street where you are at the limits of traction. It lets you find your limits and crash when you make mistakes with few significant consequenses.
I've just placed an order for a 2012 GSA, and the "Enduro ASC" is a mandatory option for the new bike.
I have traction control in both my VW Jetta GLI and 4x4 Toyota Tundra, and I wouldn't get another vehicle (2 or 4 wheeled) without it.
Here's why I want it: I live in the Seattle-area. Our region is very hilly - and also wet. There are several stop signs and controlled intersections along my commute that are on hills. When the roads are wet, and when there are grease and oil patches at the "stop line", my non-ASC RTP will occasionally spin the rear tire while leaving the stop line. I'll retard the throttle and try to get the wheel to regain traction, but in the meantime, the centrifugal forces from the spinning rear tire are trying to swing the back end of the bike to the right. With ASC, this will no longer happen.
My tires will last longer, I'll be a safer rider, and I won't have to wonder any more if my rear tire is going to spin-out "THIS TIME".
I've also been known to get caught out in the snow. Just last week it started snowing while I was at work, so I had to bail early so I could get home before the roads were impassible. My rear tire was spinning through a couple inches of slushy snow by the time I got home 40 minutes later, and in a few spots, if I didn't have any momentum, I would have been stopped in my tracks with a spinning rear tire shooting slush and snow out the back.
It's one thing to rooster-tail dirt out the back when playing off-road, but it's an entirely different matter to rooster-tail snow out the back, with the rear end of the bike trying to pass the front end of the bike as it slides around looking for traction.
It might be because it is first generation; but the traction control on my Sequoia is dangerous.
Pull out from a side road and encounter a bit of sand and the TC will cut your power just when you need it to accelerate away from the car coming at you. I had to adjust my driving to never enter traffic if an amount of extra acceleration was needed.
I understand the newer models work well; but I would have to drive one to see for myself.
What year is your Sequoia? I have a 2005 Tundra that likely has the same system. I drive my Tundra in all kinds of snow around here and up to our ski areas, so I have, quite literally, thousands of miles of experience driving my Tundra in the snow.
Given the example you've provided above, and if we have the same systems, "gunning" the engine when the rear tires have no traction will only cause your truck to spin out. If you're pulling out of a side street or driveway and turning to the right, your truck will spin clockwise as the rear tires try to get traction.
If your tires can't grip the road surface, more power is only going to make the situation worse. Closing the throttle is precisely what needs to happen. If the traction control on your truck engages, your truck is telling you that you need to adjust your driving technique to the conditions, as it's not safe to punch it and jump out into traffic when roads are icy or covered in snow.
In these situations, you should be in four-wheel drive - at least until you safely pull out into and match up with the speed of traffic.
My new GS happens to have ASC, don't know that it is a necessity, and can't say I have noticed it other than one instance when both wheels seemed not to be in contact with the road surface the engine seemed to slow dramatically. Seemed like a small price increase relative to the purchase price and I can turn it off.
Back around 85 I would never have considered ABS until we saw the BMW demo at the San Francisco motorcycle show, that sold me on the idea of ABS which is finally becoming something more accepted in the industry. Maybe BMW needs another demonstration like the ABS to show us what it is for.
In the meantime.....like I said, I can turn it off.