Why do ABS systems work so much better than traction control systems?
February 8, 2013 4:15 PM Subscribe
Why do anti-lock brake systems [seem to] work so much better than traction control systems on modern sedans?
posted by Juffo-Wup to Technology (15 answers total)
For many years I drove a car without what you might call electronic safety systems, by which I mean anti-lock brakes, traction control, and electronic stability control. Since 2010, I have been driving a 2010 Ford Fusion with all three of these systems. It seems to me that the anti-lock braking system works much better than the traction control system does, and I am wondering why this might be.
To clarify, by the "traction control system," I mean the system which tries to keep you from losing traction (acceleration) if you depress the accelerator pedal too far while driving in a straight line on a slippery surface.
When it is safe to do so, such as on an empty road or in an empty parking lot under appropriate conditions, I like to "experiment" with my car's performance in slippery conditions. I do this because I am curious about the performance and limits of the modern brake/traction/stability systems, and because I think it is important to know how one's car handles at the edges (or outside) of control in case I encounter that type of situation by mistake or in an emergency while driving.
By "experiment," I mean doing such things as:
a) Increasing brake pedal pressure on a slippery surface to see at what point the ABS kicks in and how quickly the car can stop once it does.
b) Increasing accelerator pedal pressure to see when the wheels start to slip and the traction control kicks in and how quickly the car can continue accelerating once it does.
c) Other things involving steering in conjunction with braking and/or accelerating which would normally send the car out of control, in order to see what type of order the ESC system is able to maintain.
I have been very impressed with the car's ABS system whenever I experiment with it. In every case I have tried, the ABS has been able to stop the car more quickly than I would be able to if I back off (and then modulate pressure on) the brake pedal once the ABS kicks in.
On the other hand, it seems like I can often make the car accelerate faster (in slippery conditions) if I back off and then finesse the accelerator pedal than if I simply hold the accelerator pedal at a position past where traction control kicks in and let the traction control system do its job.
[I have been *extremely* impressed with what the stability control system is able to do, even under the most extreme/unwise sets of control inputs, but that's not germane to this question.]
So, my questions are this:
1) If you drive a front-wheel-drive sedan with ABS and traction control and have experimented with or used the systems, do you agree that the ABS works substantially better than the traction control?
2) Why do you think this is? I can come up with some ideas off the top of my head (e.g., braking is frequently more safety-critical than acceleration, so they put more work/money/etc into it), but I would be very interested to hear actual engineering, mechanical, scientific, or otherwise fact-based explanations of why this might be.
Thanks in advance and, as always, I look forward to reading your input.