Photograph, ““Young woman watches as her car goes through testing at an auto emission inspection station in Downtown Cincinnati, Ohio. All light duty, spark ignition powered motor vehicles are tested annually for carbon monoxide and hydrocarbon emissions, and given a safety check. All other vehicles registered in the city receive an annual safety check. The emissions test on an exhaust analyzer went into effect in January 1975; the safety test has been in effect since 1940”, September 1975