Mercedes O309D 19-Passenger metro bus on Broadway near Horton Park in 1976. The buses were bought as part of 'San Diego Action Plan 1974' developed by San Diego Transit's General Manager Tom Prior and his staff. The goal was to grow transit usage by 50 percent by 1975 via versatility and adaptability, inherent in small buses, by increasing frequency, extending routes and adding new ones. A 1975 'American City and County' magazine article referred to San Diego as a model for the mass transit industry.