Car Owner Questions a City Employee Sitting in Her Vehicle as It Is Tested at an Auto Emission Inspection Station in Downtown Cincinnati, Ohio. All Light Duty, Spark Ignition Powered Motor Vehicles in the City Are Tested Annually for Carbon Monoxide and Hydrocarbon Emissions.
the Test Went Into Effect January, 1975. All Vehicles in the City Are Tested Annually for Safety. the Safety Check Has Been a Semi-Annual Event until the Additional Testing for the Light Duty, Spark Ignition Vehicles 09/1975. Photographer: Eiler, Lyntha Scott. Original public domain image from Flickr