Truck Parts and Service | Heavy Duty Trucking, Aftermarket, Service Info
Issue link: http://read.dmtmag.com/i/723429
preparing for the new rules, it's time the aftermarket was brought up to speed on stability control, and the impact it is likely to have on the trucking industry. Two types of stability control are prevalent in the North American truck- ing market today: roll stability control (RSC) and electronic stability control. In its fi nal rule, NHTSA defi nes the two systems as follows: "A roll stability control system is designed to prevent rollover by decelerating the vehicle using braking and engine torque control. The other type of stability control system is ESC, which includes all of the func- tions of an RSC system plus the ability to mitigate severe oversteer or understeer conditions by automatically applying brake force at selected wheel-ends to help maintain directional control of a vehicle." Both are readily available in today's marketplace, but in writing its fi nal rule, NHTSA explicitly chose ESC over RSC as the required technology for future equipment. "[NHTSA] considered requiring truck tractors and large buses to be equipped with RSC systems," the agency wrote at the time. "When compared to the ESC requirement in today's fi nal rule, RSC systems would cost less than ESC systems, be slightly more cost-effective, but would produce net benefi ts that are much lower than the net benefi ts from this fi nal rule." Safety was cited as the deciding factor. "We believe that by requiring that ESC systems be installed on the rest of truck tractors and large buses, this fi nal rule will prevent 40 to 56 percent of untripped rollover crashes and 14 percent of loss-of- control crashes," NHTSA said. "We expect that this fi nal rule will prevent 1,424 to 1,759 crashes, 505 to 649 injuries, and 40 to 49 fatalities at $0.1 to $0.6 million net cost per equivalent life saved." This distinction is important, because while RSC and ESC are both mature technologies, they're still predominately options. In its fi nal rule NHTSA estimat- ed only "34 percent of new truck tractors and 80 percent of new buses" would be equipped with ESC systems in 2018 if the systems remained elective. By committing to ESC, NHTSA has removed customers' right to choose. In most cases that can be problematic, if not devastating, for customers. This does not appear to be one of those cases. "To an extent NHTSA did this regula- tion right. They didn't rush a technology that wasn't ready," says Fred Andersky, director, Customer Solutions – Con- trols, and director, Government and Industry Affairs at Bendix Commercial Vehicle Systems. "They took their time, researched their options and made the decision to go with electronic stability control. "[ESC] can help with more situations that can end up being rollovers." As far as government regula- tions go, FMVSS 136 is impressively straightforward. The rule applies to all new three- axle truck tractors weighing more than 26,000 lbs. GVWR manufactured on or 21 Service Bay W W W . T R U C K P A R T S A N D S E R V I C E . C O M S e p t e m b e r 2 0 1 6 | T R U C K P A R T S & S E R V I C E Stability control tests are designed to simulate a rollover situation and allow RSC or ESC systems to take control of a vehicle and correct before an accident occurs.