This billboard appeared in 1980, while Iran held Americans hostage in Teheran (see pages 911–12). Gasoline shortages and rising gas prices vexed motorists all over the country. The shortages and high prices were sparked by the Iranian revolution, which brought to power Ayatollah Ruholla Khomeini, pictured on the billboard. The ad appeals to drivers to observe the fuel-saving 55-mile-per-hour national speed limit imposed in 1974 during the first oil crisis. John W. Hartman Center/Duke University Special Collections Library.