To help reduce consumption, in 1974 a national maximum speed limit of 55 mph (about 88 km/h) was imposed through the Emergency Highway Energy Conservation Act. Development of the Strategic Petroleum Reserve began in 1975, and in 1977 the cabinet-level Department of Energy was created, followed by the National Energy Act of 1978.[citation needed] On November 28, 1995, Bill Clinton signed the National Highway Designation Act, ending the federal 55 mph (89 km/h) speed limit, allowing states to restore their prior maximum speed limit.