This rulemaking would promulgate a new Federal standard that would require stability control systems on truck tractors and motorcoaches that address both rollover and loss of control crashes, after an extensive research program to evaluate the available technologies, an evaluation of the costs and benefits, and a review of manufacturer's product plans. Rollover and loss of control crashes involving heavy vehicles is a serious safety issue that is responsible for 304 fatalities and 2,738 injuries annually. They are also a major cause of traffic tie-ups, resulting in millions of dollars of lost productivity and excess energy consumption each year. Suppliers and truck and motorcoach manufacturers have developed stability control technology for heavy vehicles to mitigate these types of crashes. Our preliminary estimate produces an effectiveness range of 37 to 56 percent against single-vehicle tractor-trailer rollover crashes and three to fourteen percent against loss of control crashes that result from skidding on the road surface. With these effectiveness estimates, annually, we estimate 29-66 lives would be saved, 517-979 MAIS 1-5 injuries would be reduced, and 810-1,693 crashes that involved property damage only would be eliminated. Additionally, it would save $10-$26 million in property damage and travel delays. Based on the technology unit costs and affected vehicles, we estimate technology costs would be $55 to 107 million, annually. However, the costs savings from reducing travel delay and property damage would produce net benefits of $128-$372 million. This rulemaking is responsive to requirements of the Moving Ahead for Progress in the 21st Century (MAP-21) Act.