Nine-volt battery batteries were formerly made in this size. They had higher capacity than the then-standard carbon-zinc types, a nominal voltage of 8.4 volts, and very stable voltage. Once used in photographic and measuring instruments or long-life applications, they are no longer manufactured as mercury is highly toxic and accumulates in the ecosystem, posing a risk to humans and wildlife. Most battery voltage testers and chargers that can also test nine-volt need another snap clip to hold the battery, while cylindrical batteries often share a holder that may be adjustable in size. Because of the proximity of the positive and negative terminals
National Traffic and Motor Vehicle Safety Act initiated a campaign to prevent motor-vehicle-related injuries. In 1966, passage of the Highway Safety Act and the National Traffic and Motor Vehicle Safety Act authorized the federal government to set and regulate standards for motor vehicles and highways. The Highway Safety Act resulted in the national adoption of the Manual on Uniform Traffic Control Devices, while the National Traffic and Motor Vehicle Safety Act led to the national adoption of the Federal Motor Vehicle Safety Standards. High-Risk Populations Occupant-Protection Systems "Safety belts:" In response to legislation, highly visible law enforcement, and public education, rates of safety belt use nationwide had