AS 4191:2015 pdf download.Portable traffic signal systems.
SECTION 2 OPERATIONAL REQUIREMENTS
2.1 CONTROL TYPES
Portable traffic signal systems shall provide for the following types of control:
(a) Shuttle control (see Figure 1).
(b) Plant-crossing control (see Figure 2).
NOTE: Both types of control utilize two three-aspect lanterns (see Section 4), one facing each direction of the through road. If the portable traffic signal system is set up for plant-crossing control, the plant crosses the through road during the all-red interval, and this condition is indicated to the haul road by means of high-intensity hashing beacons (see Clause 3.3).Plant-crossing control shall only be capable of selection in manual mode by means of a lockable switch or other method affording equivalent security.
2.2 MODES OF OPERATION
Provision shall he made for the following user selectable modes of operation: (a) Manual. (b) Fixed-time. (c) Vehicle-actuated. (d) Flashing yellow. The fixed-time mode of operation shall only he available for shuttle control. The flashing yellow mode shall, in addition to being user selectable, operate automatically in response to the conditions specified in Clause 2.8.2.
2.3 START-UP SEQUENCE
2.3.1 Initial start-up
On initial start-up, the signal system shall display a flashing yellow signal to all phases for a minimum of 10 s and continue to flash yellow until such time that the settings provided in accordance with Clause 2.9.2 have been manually confirmed. The signal system shall then continue with the relevant start-up sequence (see Clause 2.3.2) for fixed-time and vehicle-actuated modes of operation; or Clause 2.3.3 for manual mode.
2.3.2 Fixed-time and vehicle-actuated modes of operation
In the fixed-time and vehicle-actuated modes of operation, the system shall be designed to start up in the following sequence: (a) Display a hashing yellow signal to all phases for minimum 10 s. (b) Display a continuous yellow signal on all phases, for the period specified in Clause 2.9.2, Item (e). (c) Display a red signal on all phases for a period equal to the longer of the preset all-red interval, but not less than 1 0 s.
2.3.3 Manual mode of operation
In the manual mode of operation. the portable traffic signal system shall be designed to start up in the following sequence:
(a) Display a hashing yellow signal to all phases for a minimum 10 s.
(b) Display a continuous yellow signal on all phases, for the period specified in Clause 2.9.2, Item (e).
(c) Display a red signal on all phases for a period equal to the longer of the preset all-red intervals, but not less than 10 s.
(d) After completion of the start-up sequence, the master controller shall remain on all-red until a further manual command is received.
2.4 START-UP INTERLOCKS
Equipment shall be provided with interlocks to prevent the portable traffic signal system from operating in other than the flashing yellow mode unless all of the essential modules are correctly fitted.
2.5 MANUAL OPERATION
In the manual mode of operation, each phase shall be individually controlled by manually entering a command for the next phase. The next phase shall not he introduced until the expiry of the minimum green time of the running phase, the yellow time and the all-red interval. It shall also be possible to allow the signals to dwell on the green aspect of either phase, or to hold on all-red. On switching to manual operation, all demands for the non- running phase shall be cancelled and the controller shall either remain in the running green phase or hold on all-red.
The manual control functions shall be so arranged and interlocked that the minimum green time and the yellow time specified in Clause 2.9.2, and the preset all-red intervals, cannot be skipped or cut short. The all-red intervals following each phase shall be capable of being selected from the all-red settings specified in Clause 2.9.2.AS 4191 pdf download.