The NHTSA revealed the final rules on the mandatory installation of electronic stability control (ESC) to help prevent rollovers on all vehicles by the 2012 model year (September 2011). The legislation applies to all vehicles under 10,000 pounds, and was ushered in without dissent by automakers. Carmakers that produce less than 5,000 cars per year will be given more time to phase in the technology.

With their increased propensity to roll over, 90% of SUVs already feature ESC, but only 40% of 2007 model cars do. Given the disproportionate fatality rate for rollovers – only 2% of auto accidents result in rollovers, but rollovers account for 40% of fatalities – having all cars equipped with ESC is estimated to reduce rollovers up to 84%, save up to 10,300 lives, and prevent up to 238,000 serious injuries per year. When it comes to single vehicle crashes, SUV rollovers could drop by 59%, with passenger cars dropping 34%.

The threshold test will be conducted at 50 mph, using a steering robot to swerve the vehicle in a predetermined pattern while the vehicle is moving at 50 mph. According to the NHTSA, the test is severe enough to cause most vehicles to spin out without ESC. Mandated equipment includes an indicator light to warn drivers about problems with the ESC.

Since ESC employs computer-controlled selective braking, all cars must also be equipped with ABS, which is a direction automakers were headed in anyway. The cost to automakers will be in the area of $985 million, but the cost-per-vehicle will only be $111, a small premium for a life saved. The cost of property damage is also expected to drop by up to $450 million per year.

One glaring weak spot is the roof. While the NHTSA has been reviewing roof strength since the '90s, proposals have been opposed by safety advocates as too weak and manufacturers as too strong.

Exceptions to always-on ESC could off-road vehicles, use on track days, driving in deep snow, and mismatched tire sizes (e.g., using a spacesaver spare). Ford and GM have indicated they expect to beat the mandatory deadline by a year.

[Source: Detroit News]