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. On November 28, 1995, President Bill Clinton signed the National Highway Designation Act, ending the federal 55 mph (89 km/h) speed limit which allowed states to restore their prior maximum speed limit.