Table of Contents

Appendix E 5.3 Selection of Controller Settings

The results of the signal timing analysis for Design 2 (Appendix E.4) can be used in conjunction with the method described in Appendix G to determine initial controller settings.

Controller operation sheets

Controller operation sheets are used to record operational specifications and all related information including controller type, signal group allocation, detector map (layout and numbering), detector functions, phasing diagram, approach timing details, controller time settings including pedestrian time settings, signal coordination details, and special functions.

Utilising the controller operation sheets, a personality to adapt a controller to the intersection is prepared by use of a generation program specific to the brand and model of controller being used. These programs require considerable experience and expertise to implement effectively. The manufacturer or a professional with expertise in the particular controller being used should be consulted.

Detectors and approach timers

Detectors and approach timers must be decided before the controller settings are determined. These are detailed below:

  1. All detectors are 4.5 m presence detectors located at the stop line in each lane, except for the C Phase right turn detector, which is an 11.0 m detector because both an arrow‑controlled turn and a filter turn are provided (Figure E 15, also Figure E 15 in Section 6.8). Individual detector loops are labelled for identification purposes. Method of labelling varies from jurisdiction to jurisdiction and may reflect detector operational functions.
  2. The approach timers are allocated as:
    – Phase A, approach timer 1: A detectors
    – Phase A, approach timer 2: C-A2 detectors
    – Phase B, approach timer 1: B1 detectors
    – Phase B, approach timer 2: B2 detectors
    – Phase C, approach timer 1: C-A1 detector (approach section)
    – Phase C, approach timer 2: C-A2 detectors.
  3. Pedestrian features will be as follows:
    – Pedestrian feature number 1: C/A pedestrian
    – Pedestrian feature number 2: A pedestrian
    – Pedestrian feature number 3: B pedestrian.

Figure E 15: Location of detectors for Design 2

GTEP 7 Figure D15

Timing card

A timing card is used to record controller settings. Part of a typical timing card completed for Design 2 is shown in Figure E 16. Values given in this figure are based on those used in the SIDRA INTERSECTION analysis for Design 2 where applicable. Dashes (-) have been used for those time settings that are not applicable. These should not be confused with zeros that, if used, would produce zero time settings.

Figure E 16: Phase and pedestrian time settings recorded on a typical timing card for Design 2

The entries in the timing card shown in Figure E 16 are discussed below. The following paragraph numbers match the time setting numbers in the timing card (and in the controller).

Phase time settings

1. Red/yellow – Not used (this controller feature is found in old sites only; practice has been discontinued and is not in accordance with current standards as seen in Part 10 of the Guide to Traffic Management) (Austroads 2019d).

2. Late start – The Phase A late start interval is used to hold the Phase C right turn red arrows at the start of Phase A in order to protect the pedestrian movement in front of the west approach.

3. Minimum green – Minimum green is Gmin = 8 s for Phases A and B, and 6 s for Phase C.

4. Increment – This is not applicable since there are no passage detectors.

5. Maximum initial green – This is not applicable since there are no passage detectors (Appendix A).

6. Maximum extension green – These are calculated as the maximum green settings (reduced values) used in the SIDRA INTERSECTION analysis less the minimum green time, Gemax = Gmax – Gmin. Therefore, Gemax = 35 – 8 s = 27 s for Phases A and B, and Gemax = 14 – 6 = 8 s for Phase C are recorded in the timing card.

It is important to note that maximum green extension settings should be selected on the basis of analyses carried out for different flow periods (Appendix E.1) to satisfy requirements of different demand patterns and different demand flow levels in those periods.

7. ECO (early cut off) green – Not applicable since there are no staged terminations of movements.

8. Yellow – The values shown are based on the calculations given in Appendix E.3.1 (point  4) and Appendix E.4.1.

9. All red – The values shown are based on the calculations given in Appendix E.3.1 (point  4) and Appendix E.4.1.

10. Special all red – There are no special all red features.

11. Gap 1 – This is the first gap setting for each phase. In Figure E 15, these are A, B1 and C‑A1 detectors. The gap setting is es = 2.5 s for A and B1 detectors, and es = 2.0 s for the C‑A1 detector.

12. Gap 2 – This is the second gap setting for each phase. In Figure E 15, these are B2 and C‑A2 detectors. The gap setting is es = 2.5 s for these detectors.

13,14. Gap 3 and Gap 4 – These are not applicable since there are only two approach timers per phase (Figure E 15).

15–22. Headway and waste – Similar to the GAP time settings, headway and waste time settings are required for the first and second approach timers only.

Headway settings are 0.7 s for A, B1, B2 and C-A2 detectors, and 0.6 s for C-A1 detector (right turn movement).

Waste settings are usually determined as 10% of maximum green values, implying 3.5 s for Phases A and B, and 1.4 s for Phase C. However, these are less than the minimum values (Table G 1). Therefore, waste settings are 4.0 s for A, B1, B2 and C-A2 detectors, and 2.0 s for the C-A1 detector.

Special all red sequences

This is not applicable.

Prohibited sequences

Transition from Phase A to Phase C (due to skipping of Phase B) is prohibited so that both approaches of Main Road display yellow signals simultaneously to avoid a possible filter right turn conflict problem for the south approach of Main Road (Section 6.5.3).

Pedestrian time settings

  1. Delay – Pedestrian delay setting is not used.
  2. Walk – Walk time is 6 s for each pedestrian movement.
  3. Clearance 1 – Clearance 1 time (Figure G 2) is 10 s for P1 and P2, and 20 s for P3. These are based on the use of clearance distances of 14 m for P1 and P2, and 26 m for P3 (Section E.3.1).
  4. Clearance 2 – Clearance 2 time is 2 s for all pedestrian movements (2 s overlap with yellow time of the terminating intergreen, i.e. with Phase A intergreen for P1 and P2, with Phase B intergreen for P3).

Auto switch

This is not applicable since actuated pedestrian movements are used (this is used for introducing the pedestrian feature automatically with the associated phase).

Pedestrian phases

This indicates the phase(s) associated with each pedestrian movement.

Other time settings

Further time settings not shown in Figure E 16 are recorded on the timing card. These include special movement time settings, presence time settings, signal coordination features, and so on.

In this example, there are no special movements, and the only presence-timed detector is the 11 C‑A1 detector (11 m long), where a presence time of 2 s is appropriate.

A-phase operates as the ‘recall’ phase to facilitate signal coordination along the north‑south approach.