The primary objective presented in this thesis is the development of testing routines and software to carry out the required tests for diagnosis of automatic traffic signal controller operation. The development of the testing routines, microprocessor software, and the inter- action in the design of the microprocessor hardware are the contributions of the author. The need by the Ohio Department of Transportation for a complete diagnostic unit that could quickly and efficiently determine if an automatic traffic controller would malfunction in operation brought about the development of such a device.
This device, being microprocessor based, simulates various traffic flow and presence conditions to the controller and in turn compares the traffic signal controller response to the correct response. Diagnosis of this type provides the most complete testing for assurance of operation or determination of malfunctions for maintenance operations. In general, the majority of maintenance time is spent in determination of the malfunction rather than the repair of the device.
Author interaction with the Ohio Department of Transportation was contributed greatly to the development of a complete set of tests to accommodate all of the electro-mechanical and solid-state controllers maintained by the State of Ohio. Feedback from the signal shop was essential in obtaining the information on types of controllers supported by the state and the characteristics of each along with present maintenance procedures.