Specifications

Vehicle Actuation (VA) operation
Signal control should always be vehicle actuated (VA) unless agreed otherwise, in writing, by the
traffic authority. You will find that modes other than VA are provided on the controller, but these
should only be used to relieve short-term difficulties.
VA reduces delay to vehicles by ensuring that the green time is adjusted automatically. The relevant
traffic authority may, however, instruct you to use another control mode, either for the duration of the
works, or for specific times of the day.
The selection may be by rotary switch, similar to that shown below, or by menu display and keypad.
All Red – holds signals on red to all approaches.
Manual (MAN) – should be used to stop traffic if the shuttle lane has to be
occupied for short periods (e.g. for unloading).
Fixed time (FT) – may be used while awaiting the arrival of the engineer if the
equipment needs attention. On some controllers there is no fixed time mode.
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