Published in 1977
A questionnaire survey was conducted to determine the types of traffic signal controls utilized by state and local agencies. The majority of the equipment was found to be supplied by three manufacturers; however, there are hundreds of different pieces of control equipment in use. Much of the equipment is quite old, and while it is relatively simple to operate, repairs are very difficult because of the unavailability of replacement parts. On the other hand, the newer equipment is very sophisticated and highly trained technicians and electricians are required to operate and maintain it. Apparently very few efforts have been made to standardize the equipment in the individual communities. Over 70% of the agencies responding to the questionnaire used equipment from two or more manufacturers, and all but two of them used a variety of models. Information on the characteristics and functions of the typical control equipment used in the state was obtained from the manufacturers and is summarized in the report.
Last updated: January 28, 2024