Which federal agency oversees the national vehicle emissions standards?

The Environmental Protection Agency (EPA) is responsible for overseeing the national vehicle emissions standards in the United States. This agency is tasked with implementing laws that protect human health and the environment, which includes regulating pollutants from vehicles and ensuring that automakers meet specific emissions standards to reduce air pollution.

The Clean Air Act is the key piece of legislation that empowers the EPA to set these standards, ensuring that all new vehicles meet regulated limits for various air pollutants, including hydrocarbons, nitrogen oxides, and particulate matter. The EPA conducts testing and provides guidelines for manufacturers to follow in order to comply with these emissions regulations, ultimately aimed at improving air quality and public health across the country.

In contrast, while the National Highway Traffic Safety Administration (NHTSA) focuses on vehicle safety standards and regulations, it does not directly handle emissions. The Federal Bureau of Investigation (FBI) is primarily a law enforcement agency and does not involve itself with vehicle emissions at all. The Department of Transportation (DOT) encompasses broader transportation policy and programs, but does not specifically oversee emissions standards as that is the role of the EPA.