A Motorist Watches Gauges on an Exhaust Analyzer as His Car Is Being Tested at an Auto Emission Inspection Station in Norwood Ohio. Since January, 1975, All Light Duty, Spark Ignition Powered Motor Vehicles in Hamilton County Must Be Tested Annually for Carbon Monoxide and Hydrocarbon Emissions.
Officials Predicted 185,000 of the 250,000 Registered Vehicles in Norwood and Cincinnati Would Be Tested by the End of 1975 09/1975. Photographer: Eiler, Lyntha Scott. Original public domain image from Flickr