Half of all new vehicles sold in Europe have it, and studies of its effects have already shown major reductions in crash-related deaths. Insurance companies in Europe offer discounts to those who purchase vehicles equipped with it.
Here in the United States only 6 percent of new vehicle buyers get it, yet all safety experts agree it is the second most effective technology (behind seat/shoulder belts) in reducing crash-related injury and death. It’s far more effective than air bags and is the only technology that can prevent the crash in the first place.
What is it?
Simply put — Electronic Stability Program, or ESP. More specifically, ESP is a combination of existing technologies that detects and assists the driver in critical situations.
Vehicles so equipped compare the driver’s intended course with the vehicle’s actual course, continually compensating for any differences.
Put another way, ESP can tell if you try to lock up your wheels in a panic stop or are about to lose control of your vehicle by, for instance, going into a turn too fast and having the rear end slide out on you.
It detects when you are going into a turn on icy roads and the vehicle starts sliding straight ahead. It detects when you might lose control on rainy streets or on sandy or gravel roads. It detects when someone is about to over-correct by giving too much steering input.
In these situations only the most highly trained drivers (police, race drivers, etc.) are skilled enough to prevent the vehicle from going out of control. Everyone else crashes, about 6,000 of whom are killed each year when the out-of-control vehicle rolls over.
ESP can — and does — prevent this from happening in all but the most extreme situations, yet most of the U.S. public is unaware that the technology is available, using hardware that is already in use on most of their vehicles.
ESP combines three proven safety systems into one.
These three are ABS, traction control and yaw control. A quick explanation of each will help to show how they can be combined to create a stability-control system
ABS, or anti-lock brakes, has been in widespread use in passenger vehicles since the mid-1980s. It works through the use of rotation sensors placed at each wheel.
These sensors are wired to a central computer that updates its information many times each second.
In emergency braking situations the sensors detect when a particular wheel is stopping its rotation, or skidding.
In that instant the computer will cut hydraulic pressure to the wheel’s brake, thus allowing it to rotate.
Because the system has the ability to perform this action on all wheels many times per second, the vehicle is prevented from skidding and the driver is allowed to steer safely while braking.
Traction control uses the ABS system’s computer and sensors to detect when a drive wheel is spinning faster than the other wheels, such as on ice or snow. The computer analyzes the situation and applies braking pressure to the spinning wheel or wheels to bring them under control.
The system is also wired to the engine management system’s computer and has the ability to reduce engine power during the period in which it is bringing the wheel-spin under control.
Reducing or eliminating wheel spin keeps the vehicle from sliding sideways, thus allowing the driver to maintain directional control.
Yaw control uses sensors that detect rotation of the vehicle about its central axis.
This system, coupled with the ABS and traction control, can prevent understeer — when a vehicle enters a turn too fast for tire adhesion and the front end tends to slide, or “plow,” out tangent to the radius of the turn, and oversteer — when during a turn the rear end loses traction and slides out, causing the vehicle to spin.
When the yaw control sensors detect an impending loss of control, the system applies braking pressure to individual wheels and controls engine power to correct understeer and oversteer tendencies. It does this through the use of powerful computer programs that calculate how the vehicle is reacting, updating information hundreds of times per second.
Designers of the three systems realized several years ago that they could be combined to prevent loss of vehicle control in most common situations. All it took was some software development that integrates all three systems into one.
ESP is essentially an electronic “co-pilot.” It helps drivers avoid crashes by detecting when they have overcorrected or applied too much braking pressure or are entering a curve at too high a speed.
ESP is particularly effective in preventing SUV rollovers, a growing cause of highway deaths. SUVs are less stable than cars because of their much higher center of gravity and tend to roll over when there is a loss of control and the vehicle goes off the road.
It makes sense to install ESP on new SUV models and it makes even more sense for the National Highway Traffic Safety Administration (NHTSA) to mandate it. After all, NHTSA mandated air bags, a technology that has saved about 8,000 lives in the past 12 years. ESP could save that many lives in two or three years, at far less cost per vehicle.
Is ESP foolproof?
No, because fools are so clever. However, ESP can be considered the “great equalizer” of automotive technologies. It makes good drivers out of poor ones by taking control before it is lost. That’s a powerful tool.
One of the largest manufacturers of ESP is Continental Teves (it makes Continental tires as well).
It supplies the systems to the automakers below under the following names:
Audi, Mercedes-Benz, Volkswagen — ESP
BMW, Jaguar, Volvo — Dynamic Stability Control
Ford, Lincoln, Mercury — AdvanceTrac
Porsche — Stability Management System
Toyota — Vehicle Skid Control