Basic Characteristics and Functions of Traffic Signal Equipment

Report No: 77-R53

Published in 1977

About the report:

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.

Disclaimer Statement:The contents of this report reflect the views of the author(s), who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement.


Other Authors

R. N. Robertson

Last updated: January 28, 2024

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