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21st Century Operations Using 21st Century Technologies

Model Systems Engineering Documents for Central Traffic Signal Systems

Appendix G. Glossary


Central Traffic Signal System: The system that manages traffic signal databases and monitors the operation of traffic signal controllers. The software communicates with the traffic signals in the field from a central location such as a TMC.


Commercially available Off-The-Shelf. This is an FAR term defining a non-developmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract in precisely the same form as available to the general public.


Contract awarded to the "lowest responsible bidder". Bid is based on a complete set of plans and specifications that precisely defines the facilities to be built.

Natural cycle length

The cycle length at which an intersection would run with minimum overall delay.


Activity that occurs simultaneously with or very soon after an event. For example, real-time control involves taking action based on measurements immediately after the measurement is completed.


The project-specific detailed requirements for a CTSS to be purchased by an agency or a statement by a manufacturer defining the detailed features provided by the CTSS.

Synch point

Reference point in signal phase or cycle used to synchronize operation of adjacent signals.


Traffic Signal System, short for CTSS, Central Traffic Signal System

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