[enjalot]

I think you should keep in mind that you appear to be an intelligent, skilled and avid driver. For you driving is an experience you take seriously and also seem to enjoy. I'm not worried about what you do on the road, but I am worried about the millions of less intelligent and skilled drivers that are pushing 3000lbs of metal around at lethal speeds.

I think you are justified in wanting and buying a machine that suits your needs, but please don't assume that everyone is or even should be as adamant about driving as you are. I for one will happily let the computer take the wheel and allow me to focus on things I care about like conversation or coding. If I want a joy ride hopefully I'll be successful enough to own a classic gasoline powered driving machine ;)

[mostapha]

Driving at a high level is one thing. It requires a lot of skill and concentration.

Not killing people is completely different: it requires basic skills and some small measure of multi-taking ability. Which is more important, reacting to the car changing lanes without a signal in front of you or finishing your sentence RIGHT NOW?

The problem isn't even skill level. Driving normally at city and highway speeds is easy. The vast majority of 1st world residents know how to do it, and very very few of them make mistakes severe enough to affect anyone else's lives. The average driver is nowhere near as bad at it as most people seem to think.

But taking the driver's commitment to and awareness of the risks inherent in driving away and placing that burden on active "safety features" is a bad thing. I know their hearts are in the right place and that I'm not the person these systems are designed for. But they're going to get people killed.

My issue with Mercedes's Traction Control in particular isn't even that it makes drivers lazy. It's that in at least that situation, it can't tell the difference between power-induced oversteer and breaking-induced oversteer. In that situation, it reacted EXACTLY WRONG. It doesn't matter whether the driver is competent or not if the system makes the opposite changes that it should.

[DrewG]

It's not the average drivers that need help, its the bad drivers. The ones who roll through a red light turning right, but look left the entire time, which is a very common way for pedestrians to get hit by cars. The system in the article would probably prevent tons of those accidents. I'm all for taking control away from bad drivers, even if that means we also have to take control away from the average and good drivers.

[mostapha]

And if they're running through a red light, that means the cross street has a green.

The pedestrian might be in slightly less danger if the car reacts properly. But then the car stops unexpectedly and the driver wonders what happens…and winds up stopped in an intersection for some nonzero amount of time.

Also, unless I'm visualizing this wrong (right turn on red hits a pedestrian in the crosswalk to his right that's parallel to his original direction of travel) the only way the pedestrian would have been in that crosswalk at all is if s/he was crossing against the light and crossing the path of cars going straight on a green.

[DrewG]

The ped is travelling perpendicular to the original direction of the car (crossing from right to left from the cars point of view) and is most likely just stepping off the sidewalk.

[bradleyland]

I'm not sure I'll be able to change your mind about this, but I'd like to express my opinion on your sentiment and leave it at that.

I think that maybe you're wrong about a few things here. First and foremost, that your slide was recoverable.

I'm a car guy myself. Like you, I insist on manual transmissions with rear wheel drive. I've been to driving schools, read extensively about how suspension affects handling dynamics, and turned a few wrenches in my time. Even with all that, I try to remain humble about my own driving abilities and the fact that while I enjoy it, I don't drive professionally, so I shouldn't expect professional results.

Your comments about skid recovery apply to the input controls that are available to you as the driver. They don't apply to the input controls available to the traction control systems in your car. For every subtle detail that you learned about handling using the steering wheel, brake, and clutch, there are equivalents for the systems available to the traction control system, such as individual wheel braking.

Stopping a slide is about controlling rotation. You cannot use the brake to directly rotate the vehicle because you only get one brake pedal. The best use of that brake pedal, as a driver, is in controlling the speed and weight distribution of the automobile. That is the most you can hope for.

"My issue with Mercedes's Traction Control in particular isn't even that it makes drivers lazy. It's that in at least that situation, it can't tell the difference between power-induced oversteer and breaking-induced oversteer. In that situation, it reacted EXACTLY WRONG. It doesn't matter whether the driver is competent or not if the system makes the opposite changes that it should."

The stability program in a Mercedes absolutely knows the difference between power-induced oversteer and braking-induced oversteer. It uses accelerometers, yaw sensors, throttle position sensors, and individual wheel speed sensors to infer your intended direction of travel. Braking the outside rear wheel does transfer weight forward, but it has a far more significant positive effect on correcting rotation because of the asymmetrical application of braking force. Your slide was simply unrecoverable. You think that it was recoverable, but you'll never know for sure. Based on the physics involved, I think you're wrong.

I've tested the limits of these systems myself. My 2006 GTI had ESP. I took it out to a dirt road and explored the limits under slalom conditions and hard turns. These systems are amazing at recovering slides that can be recovered. If I pushed hard enough, I could "break through" to an uncontrollable slide, however. When you "overshoot" your mark, brake, turn, then hit a rumble strip (which significantly reduces available traction) you end up in an unrecoverable slide.

The irony here is that your Mercedes' ESP system didn't almost kill you, you did.

[encoderer]

Thanks for offering your opinion. While I want to respect the GP's personal experience, your comments echo my feelings. My favorite part of a Mercedes (and this is surely true for other premier makes) is that everything seems to have been thought out and engineered ^1. And with my own personal experience of the cars TCS, I felt it very hard to believe that the Mercedes TCS would be so simplistic.

^1 Not to say I don't have my issues with the cars -- stuff like a crappy Chinese made iPod interface.

Edit: That video is stunning. Thanks for the share.

[bradleyland]

I'd strongly encourage you to take advantage of any driving school that Mercedes offers. I've read countless messages from individuals who insist that these safety systems (ABS, TCS, and ESP) are a detriment to their ability to drive the car, but I've experienced them in two makes of automobile (VW and BWM) now, and I now know from first-hand experience that they work fantastic. There is no replacement for testing them out for yourself.

[bradleyland]

To support my point, here is a video of Tiff Needell testing an older version of ESP in a Jaguar on a sheet of ice. The ability of the system to stop a car from sliding out of control under these conditions is just mind boggling.

This 6:21 start point shows both (with/without) tests:

http://www.youtube.com/watch?v=j-hHWSQhKuc&feature=fvwre...

[DrewG]

I'm afraid this is whats going to prevent adoption of more automatic cars. The people who care about cars don't want the features, but its the people who don't care about cars that would benefit most. And they don't pay attention.

[mostapha]

Once again, they won't benefit if the systems aren't a hell of a lot better than Mercedes was capable of producing in 2006.

And unless you know what's going on "under the hood" well enough to either evaluate their code or design a real-world test that you can perform in an empty parking lot…you're left to decide based on what Mercedes says. And they're never going to say "our system can't detect the cause of a skid…it just reacts based on detecting the speed wheels are spinning and assumes the driver is completely incompetent."

Some of the systems are great. There's no reason a car sold today shouldn't have ABS: the driving techniques required to get similar performance out of non-ABS brakes are very skill specific and time-intensive to develop. It's not worth it for >99% of drivers. And there are "good" traction control systems. Subaru's computer-controlled differentials in their AWD system are pretty good. But that system isn't capable of making a mistake as bad as the "active braking" systems that are coming out.

[DrewG]

So you are in favor of technology that takes control away from drivers as long as it works? Perhaps we are actually on the same page here...