Multi-message sign arrangement#

All panels in a multi-message frame are to be filled (if required, by a yellow blank – Queensland MUTCD Part 3 Clause 4.4.2(e) and Appendix B). In the Queensland MUTCD, the REDUCE SPEED multi-message panel (TC1220 or TC1712) may only be used to supplement a speed restriction (or speed limit AHEAD) panel where a speed zone reduction is implemented or on the initial speed restriction sign on approach to the site where this sign is used as a repeater speed restriction sign for traffic approaching / entering the site.

The reason for a temporary speed restriction sign should be clear to the road user. Where speed restrictions are applied for roadworker safety purposes, as is the case for the 40 km/h speed zone past the work area, the speed restriction sign should be used in conjunction with the WORKER (symbolic) sign (QGTTM Part 3 Section 5.5.1 Operational) In this scenario, the Designer has chosen to use the REDUCE SPEED panel (1200 x 300), with a WORKER (symbolic) panel and the 40 km/h speed restriction sign. The 40 km/h speed restriction panel is placed closest to traffic (Queensland MUTCD Part 3 Clause 4.4.2(c)).

  • For requirements on the use of the REDUCE SPEED message in Queensland, refer to Queensland MUTCD Part 3 Appendix A and Table A.2.
  • For information regarding the WORKER (symbolic) sign, refer to Queensland MUTCD Part 3 Clause 4.6.5.
  • For requirements and information regarding the use of multi-message signs, refer to Queensland MUTCD Part 3 Clauses 4.2.2, 4.4.4 and 4.5.2, and Appendices A and B.
  • For information and requirements for speed zones, refer to QGTTM Part 3 Section 5.5.

6. As the traffic control station is to be located in the single lane section, traffic control devices for traffic control will be considered now rather than later in the process (as per QGTTM Figure 5.1) which would be typical when the traffic control station is in advance of the transition (taper) area. Traffic in the 'open' lane will be required to be stopped for generally short periods (but may be up to a maximum of 10 minutes at a time) to enable truck and plant movements at the work area. This is achieved by using traffic controllers, with this site requiring a portable traffic control device (PTCD). In the QGTTM, PTCDs are recommended at all sites with a permanent speed limit of 70 km/h or greater and an annual average daily traffic (AADT) of greater than 500 vehicles per day; however, it is important to note that PTCDs may be used on any sites (even if not meeting this requirement). In this scenario, the permanent speed zone is 100 km/h and a PTCD would be recommended. Even without an AADT value being provided, as this site is multi-lane and divided, it would be expected that the traffic volume would be in excess of 500 vehicles per day. A boom barrier has been selected by the Designer as the PTCD to be used at this site. The traffic control station is to be located in the single-lane section in the additional warning area (clear of the safety buffer). The traffic control station will also need to be one sign spacing (from Table 2.2 and a 60 km/h speed zone, use 45 m) in advance of the 40 km/h speed restriction sign for the work area to provide for separation between different traffic control devices (for example, between the boom barrier and work area speed zone sign). The traffic controller operating the boom barrier is to be located in a position of safety, taking into account the requirements in QGTTM Part 7 Sections 2.6.2 and 2.7.3. As works are occurring at night, the traffic control station (boom barrier) will require illumination (as will the work area, lane closure and taper).

  • For considerations regarding traffic control placement / signage, refer to AGTTM Part 3, Section 5 10.2 and QGTTM Part 7.
  • For information regarding the choice of manual traffic controllers or PTCDs, refer to QGTTM Part 3, Section 5.10.1.
  • For recommended spacing of signs (and between traffic control devices), refer to QGTTM Part 3, Table 2.2.
  • For information and considerations regarding night works, refer to QGTTM Part 3, Section 6.7 and for traffic control at night QGTTM Part 7, Section 2.6.5.

7. Calculate the expected maximum queue length for the traffic control station from the provided five-minute maximum traffic count of 12 average vehicles and one large vehicle. For a 10-minute delay and using Table 4.3 to estimate the queue length for this scenario, provides an estimated queue length of 184 m (12 x 12 + 1 x 40) for the maximum 10-minute delay period.

  • For information about estimating the queue length, refer to QGTTM Part 3, Section 4.8, and Table 4.3.

8. Determine the advance warning signs for the traffic control station. A STOP HERE WHEN DIRECTED sign is optional in the Queensland MUTCD Part 3 (as per AS 1742.3); however, in this scenario, the Designer has chosen to install this sign which is placed 6 m in advance of the traffic control station (also within the additional warning area). As the estimated queue length of 184 m is between 145 m and 204 m, a primary and an additional PREPARE TO STOP (PTS) sign is required (Figure 4.4). The primary PTS sign is located a distance as per Table 2.3 in advance of the predicted end of queue. In this scenario, assuming the 60 km/h sign is more than 200 m in advance of the primary PTS sign location, the sight distance to the end of queue for a 60 km/h zone is 90 m. Locate the primary PTS sign at least a distance of 280 m (6 m from the queue stopping point + 184 m queue + 90 m sight distance) from the traffic control station (also see Note 14 for an adjustment in this distance due to spacing requirements for other traffic control devices). The additional PTS sign is located 120 m from the traffic control station.

In the QGTTM Part 3, the primary PTS sign may be substituted for a QUEUED TRAFFIC AHEAD sign when there is either a repeater PTS sign or an additional PTS sign in place. In this scenario, the Designer has chosen to use the QUEUED TRAFFIC AHEAD sign as the primary PTS sign, as the primary risk at this point for approaching traffic is the end of queue, not what sort of traffic control is provided at the traffic control station (which is shown on the additional PTS sign located closer to the traffic control station). The QUEUED TRAFFIC AHEAD sign assembly as shown in QGTTM Part 3, Figure 4.8 includes the PREPARE TO STOP panel in a 1200 x 300 size (TM1-18B) which is permitted in the Queensland MUTCD Part 3 (and AS 1742.3) but prohibited by AGTTM Part 7.

  • For considerations regarding traffic control placement / signage, refer to QGTTM Part 3, Section 4.8 and QGTTM Part 7.
  • For information regarding when a STOP HERE WHEN DIRECTED sign is an option in Queensland, refer to QGTTM Part 3, Section 4.8 and Queensland MUTCD Part 3 Clause 4.7.2(d) and Clause 4.7.5(c).
  • For information regarding using a QUEUED TRAFFIC AHEAD sign in Queensland, refer to QGTTM Part 3, Section 4.8.
  • For sight distance requirements (end of queue), refer to QGTTM Part 3, Table 2.3.
Source: TN195 TGS Worked Examples · pages 8–11 Open PDF at this page Search this document