The government agency believes that the decision could save as many as 49 lives per year and prevent up to 1,759 crashes.
NHTSA's rule applies to semis or buses with a gross vehicle weight rating of 26,000 pounds or greater, and truck makers have some time to comply. For big rigs, ESC is required in two years. Buses over 33,000 pounds get three years, but those between 26,000 (12 tonnes) and 33,000 pounds (15 tonnes) have four years to fulfill the requirement.
ESC should especially help prevent semis from rollover crashes, possibly by as much as 56 percent in some cases, according to the agency's statistics. The systems use sensors to brake the necessary wheels to keep the trucks under control. NHTSA has recommended the tech for heavy vehicles since 2011, and it has been a requirement for passenger models since 2012.