At the same time coachbuilders met downsizing in the automotive industry, the federal government in the United States updated its requirements concerning minimum width, headroom, and equipment levels of emergency vehicles. These changes were part of the 1973 National EMS Systems Act, which was passed by Congress in 1974, and implemented four years later (in 1978). In order for communities to receive federal funds, their ambulances were required to meet updated federal specifications. Passenger-based vehicles were purposely excluded from legislation and the last American-made automobile-based ambulance was built in 1978.