Electronic Stability Control

By Drew Wikstrom

The best option shouldn't be an option

Many ideas and solutions have been touted over the years as "the answer" to keeping vehicles under control and on the road. "Stay alive drive 55", all wheel drive, antilock brakes and other more esoteric ideas have been pumped up by the media in the past and then failed to deliver any meaningful reduction in single vehicle accidents. One solution has finally achieved a measurable decrease in unintended off road excursions. The solution is ESC or Electronic stability control. ESC reduces single vehicle accidents by helping the driver maintain control of the vehicle in situations that might normally send the vehicle out of control.

According to Car and Driver magazine's editor-in-chief Csaba Csere two recent studies, one performed by the National Highway Traffic Safety Administration and the other by the Insurance Institute for highway Safety found meaningful reductions in single vehicle accidents. In his February 2005 editorial "The Steering Column" Mr. Csere writes: "The NHTSA study found that vehicles fitted with ESC had 42 percent fewer single-vehicle crashes and 40 percent fewer fatalities in those crashes. The IIHS study results were even more positive, with single-vehicle crashes declining by 41 percent and fatalities in such crashes plunging by 56 percent."

As I read Mr. Csere's article further he delved into a description of ESC technology and how it works. This in itself wasn't news to me (and I'll get to it a little later). What really caught my attention was the reason he feels that ESC has proven to be so good at preventing single vehicle accidents. ESC doesn't require any alteration of the driver's habits. If you are driving a car with ESC and it starts to skid all you have to do is what driver's have been doing since high school driver's education, steer in the direction you want to go. No change in technique, no instructions required. Just drive the car in a reasonable direction. This follows the KISS acronym that I am so fond of: "Keep It Simple Stupid".

Because ESC statistically reduces single vehicle accidents in my opinion it is the single best active safety system that can be purchased in any motor vehicle today. It is so good that it should be standard equipment. The driver doesn't need to to anything different to make it work or to get the maximum benefit from it. It is actually a perfect representation of transparent technology. You don't have to turn it on. You don't have to use a different technique. You the driver just have to drive the car. That is what makes stability control so good. Everyone driving can use it, and if a car is equipped with it, it is nearly guaranteed that it will be used, even if the driver doesn't know he or she activated the system.

Admittedly a skilled driver won't find much benefit on a dry road, and in a performance environment such as a high performance track day or an autocross a skilled driver may drive faster with the system turned off. I'm sure to get an email from the sports car driving purists among you, and at least one of you will tell me that ESC just gets in the way; but what about when we are not driving sports cars, or even if we are, what if we're driving to work, or driving in the rain or snow. Even a supernaturally skilled driver will benefit from the system in inclement weather on the street. The fact is even the best of us aren't always driving with maximum focus or maximum skill. We can also be surprised by any number of unforeseeable situations on the street that can cause us to lose control of the vehicle we are driving. This is true of natural phenomenon like weather and ice or simply avoiding dangerous situations created by other motorists.

“How does it work?”

ESC technology goes by a veritable alphabet soup of names and acronyms depending on the vehicle manufacturer: ESC, ESP, DSC, DSTC, PSM, VDCS, VSA, VDC , Advanced Handling, StabiliTrak, AdvanceTrac and more. Each of these acronyms is just a marketers name for electronic stability control. Semantically they all mean the same thing and they all work in the same way.

The ESC Coalition (www.esceducation.org) describes ESC as "a stability enhancement system designed to electronically detect and assist the driver in critical driving situations. ESC compares a driver's intended course with the vehicle's actual movement. When instability is detected, ESC automatically applies brakes to individual wheels and can also reduce engine torque to help keep you on track."

ESC systems take information from individual wheel speed sensors, a steering wheel angle sensor, a yaw rate sensor, a lateral acceleration sensor, and a brake system pressure sensor. A computer program takes these values and determines when your vehicle is skidding and what direction you actually intend to travel in. It then performs exactly as the quote above describes to keep your car under control.

The system does not and can not defy the laws of physics. It is still possible to make a totally harebrained maneuver and send your vehicle off on an unplanned agricultural mission where it will acquire specimens of dirt, tree bark and shrubbery, and probably get a really awful sheet metal makeover. If you have a normal brain and are driving your vehicle within the laws of nature ESC can and will save you from a possible vehicular catastrophe.

If you are looking for new cars, or a recent used car, try to choose one with ESC, you'll be glad you did.