3Description and use of closure devices#

The traffic management requirements for a tunnel closure, herein called closure, are divided into three stages:

  1. 1.warning
  2. 2.physical closure, and
  3. 3.re-opening.

In the case of an unplanned closure, Stage 2 shall be enacted as soon as practical after Stage 1. The time between the initiations of the two stages will be dependent upon each situation and as specified / agreed by the road network owner/s. In the case of a planned closure, the time between the initiations of Stage 1 and Stage 2 will generally be the time for a vehicle to travel from the first warning device on the motorway / freeway to the tunnel portal.

3.1Stage 1 – Warning#

Stage 1 consists of the following components:

  • a) variable message signs (VMS)
  • b) warning signs
  • c) LED in-pavement lights
  • d) variable speed limits signs
  • e) audible alarm, and
  • f) public address system.

These warning devices are located on the mainline, at the diverge, and on the ramp to the tunnel itself and are to be activated simultaneously in the event of a closure. Refer to the Standard Drawings for a comprehensive layout of these devices.

3.1.1Variable message signs#

As a minimum, a VMS is to be provided prior to the last decision point before the tunnel exit. This sign is to be used to inform motorists of the closure and to encourage the use of alternative routes. A VMS is to also be provided at the tunnel portal, directly above the entrance. In the event of a closure, this VMS will display the text TUNNEL CLOSED / ALL VEHICLES STOP / WAIT FOR / EMERGENCY SERVICES. All VMSs shall comply with the requirements of the Austroads Guide to Traffic Management, the Queensland Manual of Uniform Traffic Control Devices (MUTCD), and Technical Specification MRTS202 Variable Message Signs.

3.1.2Warning signs#

The following warning signs are to be provided both on the mainline and at the diverge:

  1. a)Advance warning signs in the form of changeable message signs (CMSs) are to be used in conjunction with any tunnel advance static direction signs on the motorway, typically 1 km and 500 m prior to the exit. The CMS panels are to be incorporated into the static direction signs such that the text 'TUNNEL CLOSED' can be displayed in the event of a closure (see Standard Drawings). Additionally, two alternately-flashing yellow lights, each complying with the requirements of Australian Standard AS 2144 Traffic signal lanterns, are to be positioned on either side of the CMS panel and will be activated when the CMS displays the closure message. All CMS shall comply with the requirements of the Queensland MUTCD and Technical Specification MRTS227 Changeable Message Signs. The locations of all advance direction signs shall comply with the requirements of the Queensland MUTCD.
  2. b)Additionally, a flashing static warning sign is to be provided on the approach side of the diverge from the motorway or freeway to the tunnel ramp. The sign is to display the text TUNNEL CLOSED WHEN FLASHING, DO NOT EXIT. Two alternately-flashing yellow lights, each complying with the requirements of AS 2144, are to be provided in both top corners of the sign and will be activated in the event of a closure. The static sign shall comply with the requirements of the Queensland MUTCD.

3.1.3LED in-pavement lights#

Red Light Emitting Diode (LED) in-pavement lighting (IPL) is to be installed in the pavement along the full length of the continuity line at the diverge from the motorway to the tunnel ramp. The lights shall have dimensions that comply with the requirements of Australian Standard AS/NZS 1906.3 Retroreflective materials and devices for road traffic control purposes, Part 3: Raised pavement markers (retroreflective and non-retroreflective). The lights are to be spaced in accordance with the Queensland MUTCD Part 2 Traffic Control Devices for General Use. The IPL will only be activated during the event of a closure, that is, no IPL will be used during normal operating conditions. When activated, the IPL is to remain fully lit.

3.1.4Variable speed limit signs#

Variable speed limit signs (VSLS) are to be provided on the tunnel ramp to reduce the speed in the event of a closure. The signs shall be located as close to the diverge as possible while still being apparent to motorway traffic that the speed applies to the ramp only. In the event of a closure, these signs shall reduce the ramp regulatory speed limit. The maximum posted speed limit on the ramp during a closure shall be 60 km/hr. All VSLS shall comply with the requirements of the Austroads Guide to Traffic Management, the Queensland MUTCD, and Technical Specification MRTS206 Provision of Variable Speed Limit and Lane Control Signs.

3.1.5Audible alarm#

An audible alarm is to be located at the tunnel portal to provide an audible warning of the closure where use of the tunnel by people walking or riding bikes is permitted.

3.1.6Public address system#

A PA system shall be used at the tunnel portal where use of the tunnel by people walking or riding bikes is permitted.

3.2Stage 2 – Physical closure#

A physical barrier must be installed to prevent traffic driving into the tunnel when the occurrence of an incident requires full closure of the tunnel carriageway. The physical barrier must incorporate the following components:

  • a) boom gate/s, and
  • b) dual-aspect traffic signals.

Where a turnaround facility is not provided within 200 m of the tunnel portal, the traffic management measures for Stage 2 shall be duplicated just prior to the turnaround facility.

Stage 2 may be activated automatically after a predetermined period of time after the initiation of Stage 1, or manually by an operator at the Tunnel Traffic Management Centre (TMC).

3.2.1Traffic signals#

Dual-aspect traffic signals are to be mounted and operated as follows:

  1. a)For carriageways with two or more lanes, one set of signals is to be provided on each side of the carriageway. For single-lane carriageways, one set of signals is to be provided on the left-hand-side of the carriageway only.
  2. b)Each set of signals must be mounted horizontally on the side of the carriageway, just prior to the boom gate/s.
  3. c)They shall be used in conjunction with an R6-6 STOP HERE ON RED SIGNAL sign.
  4. d)Each set of signals must be housed in a single mounting enclosure and consist of dual red aspects.
  5. e)When activated, the dual red aspect signals in each set must flash alternately with an adjustable mark space ratio of 1.1:1, a cycle period of 1.1 seconds and must be adjustable in the range 0.5 to 3.0 seconds in 0.1 second increments. The flash controller must provide an overlap in ON time so that, at any instant in the cycle, at least one aspect is energised.
  6. f)A white stop bar is to be painted on the pavement at the same physical location as the signals.

The signals must comply with the requirements of AS 2144, the Queensland MUTCD, and Technical Specification MRTS93 Traffic Signals. All signs and pavement markings must comply with the requirements of the Queensland MUTCD.

3.2.2Boom gate/s#

A boom gate is to be provided at the tunnel portal. Where there are two or more lanes at the portal, two boom gates are to be used with a maximum clearance of 2 m between booms. The boom gate/s must incorporate the following features:

  1. a)the boom arm is to move from a vertical to a horizontal position; when in the 'closure' position, the boom gate is to always remain perpendicular to the traffic stream
  2. b)the boom arm is to be red-and-white striped and is to be fitted with high visual impact red flashing lanterns that are activated when the boom gate arm starts to lower; the boom arm design is to comply with the requirements of the Queensland MUTCD Part 7 Railway Crossings
  3. c)there is to be a panelled section that extends from the boom gate arm to the road surface when the gate is in the closure position
  4. d)the gates are to lower via a jog switch mechanism which allows the boom to be lowered in partial movements to increase visibility, and
  5. e)there is breakaway of the boom gate arms at vehicle speeds of greater than 10 km/hr or bends and distortion at lower-speed impacts.

The boom gate may be lowered automatically after some period of time after the initiation of the flashing red signals or manually by an operator at the Tunnel TMC. Where pedestrian and/or cyclist use of the tunnel is permitted, separate gates are to be provided on these paths.

3.3Stage 3 – Re-opening#

The re-opening procedure will be dependent upon each situation and shall be outlined in the tunnel's operational plans. Generally, once all physical closure devices have been removed, warning devices shall not be switched off until it is safe to do so as determined by the Tunnel Operator.

Source: Tunnel Closures TM Guideline · pages 5–9 Open PDF at this page Search this document