The seat belt -- a simple, inexpensive piece of equipment -- has saved huge numbers of lives and limited serious injuries in crashes since they were mandated in all passenger vehicles in the mid-60s. Since 1975, when only about 20% of people used them, seat belts have been documented by NHTSA (the National Highway Traffic Safety Administration) to have saved over 135,000 lives and prevented countless serious injuries. It has been only recently that seat belt use reached the 80% level -- an impressive statistic, nonetheless.
Now poised to enter into automotive history as what most experts consider the second most beneficial safety device: ESC, or Electronic Stability Control, is a device that makes skilled drivers out of everyday operators of motor vehicles. Think of it this way: imagine driving down a winding road in the rain and suddenly encountering a tight turn. You're going too fast for the conditions and any attempt to brake or turn is going to result in loss of control and a dangerous skid sideways. Now imagine that you're in the same vehicle with a NASCAR or Formula 1 race driver at the wheel. He/she can easily bring the vehicle into control because race drivers have extensive training and practice in recognizing changing vehicle dynamics while the vehicle is at the limits of adhesion. The driver would easily be able to make the correct adjustments to steering, braking and power to safely negotiate the situation.
Electronic Stability Control (ESC) takes the place of that highly skilled driver in any vehicle. It utilizes the technology inherently available in ABS (Anti-lock Brake System) and Traction Control systems to control a vehicle's tendency to lose directional stability. Using a system of sensors that detect lateral acceleration, yaw and wheel speeds, ESC computer software determines the degree to which the vehicle is plowing (understeer) or fishtailing (oversteer) and selectively applies braking pressure to individual front or rear wheels and reduces engine power to bring it under control. All this happens so quickly that most drivers wouldn't notice that anything is wrong.
The effectiveness of ESC in helping the driver maintain control of the car has been confirmed by many studies in the U.S. and internationally. In the fall of 2004, the National Highway Traffic Safety Administration (NHTSA) released results of a field study on the effectiveness of ESC in America. NHTSA concluded that ESC reduces the incidence of crashes by 35%. In addition, the Insurance Institute for Highway Safety (IIHS) states that up to 10,000 fatal crashes could be avoided annually if all vehicles were equipped with ESC.
Enter the SUV
According to current safety data, over 10,000 people each year die in rollover crashes and nearly half of the fatalities involve SUVs and light trucks. This is a growing safety issue, since SUVs and light trucks are three times more likely to roll over in a single vehicle crash than a passenger car. Several years ago NHTSA started compiling data on rollover crashes, primarily involving SUVs and light trucks. As these vehicles gained popularity with the buying public; the incidence of such crashes dramatically increased because drivers weren't familiar with the different handling characteristics of high center-of-gravity vehicles. Some of the very things that drew people to SUVs and minivans -- tall "greenhouse," stiff suspensions, 4-wheel drive, high ground clearance, heavy and strong construction -- also made these vehicles more prone to loss of control and rolling over. Clearly something had to be done...
Now that SUVs and minivans comprise nearly half of all new vehicle purchases it falls upon NHTSA to mandate safety systems that will make operation of these vehicles and passenger cars more predictable and directionally stable in all conditions. A NHTSA NPRM (Notice of Proposed Rulemaking) is now at the Office of Management and Budget and is expected to get through the review process as early as the end of this congressional session. The NPRM will encompass the minimum rollover/loss of control safety standards that will be mandated for new models. These standards will be based upon predictable test models in which repeatable data can be demonstrated (one such model is the "J" turn, in which radical steering input is introduced to cause a vehicle to fishtail).
After the NPRM is issued all auto manufacturers will have at least 60 days to comment before a final rule is issued. When the rule becomes law (presumably, by spring 2007) a phase-in schedule for SUVs and light trucks is most likely to begin in 2008. Ultimately, all vehicles will be required to be equipped with some form of ESC. NHTSA estimates the costs will range from $300 to $800 per vehicle, depending upon model and drivetrain configurations.
What Do Automaker Say?
Vehicle manufacturers welcome this new standard. In fact, nearly all manufacturers already offer ESC on some of their product lines and three (Hyundai, Toyota and Honda) have announced that all their new models will be so equipped from now onward. This is great news for automotive safety and for everyone who shares the highway.
ESC is currently not retrofittable to older vehicles, unfortunately, because its complex software and sensor integration must be done during the initial design of the vehicle'?? architecture. This doesn't preclude some company from eventually marketing a "semi-ESC" device for older vehicles, but there is no way of predicting if/when such technology will be developed. Meanwhile, below is a worldwide listing (provided by Continental Automotive Systems) of which vehicle manufacturers use electronic stability control systems under different marketing names: