A temporary road closure is signed as a sequence, not a single sign. Traffic approaching the works gets advance warning with a ROAD CLOSED AHEAD sign, the closure point itself carries the ROAD CLOSED sign, and AS 1742.3 requires barrier boards completely barring access to the roadway to be used with it. From there, a signed detour carries traffic around the closed section, from DETOUR AHEAD through the directional detour panels to END DETOUR where road users rejoin their original route. This guide walks through that sequence in order, sign by sign, and maps each one to the corflute panels that carry it in a multi message frame.
In this article
- What signs does a temporary road closure need?
- What if local traffic still needs access?
- How is a detour signed from start to finish?
- What about side roads?
- What are barrier boards and when are they required?
- What about lane closures?
- Frequently asked questions
What signs does a temporary road closure need?
Two signs do the core work. In advance of the closure, ROAD CLOSED AHEAD warns approaching traffic that the road ahead is shut, giving drivers the chance to divert early. At the position where the roadway is actually closed, AS 1742.3 says the ROAD CLOSED sign shall be used, and it does not stand alone: barrier boards completely barring access to the roadway shall be used in conjunction with the sign. A ROAD CLOSED panel on a frame with an open road behind it is not what the standard describes.
The standard also says consideration should be given to providing traffic detours, which is where the second half of this guide comes in. And note the boundary: this is temporary works signage. A permanent road closure uses sign G9-20 in accordance with AS 1742.2, which is different territory altogether.
600x600mm corflute panel warning approaching traffic before the closure point. Also available in 1200x600mm (TM1-43C).
The panel that stands where the roadway is closed, used with barrier boards barring access. Also in 1200x300mm (TM2-4B) and 1200x600mm (TM2-4C).
What if local traffic still needs access?
Plenty of closures shut a road to through traffic while residents and businesses still need to get in. The standard covers this directly. Where the road is closed but the detour occurs at an intersection in advance, and local traffic access is required, the signing at the detour location should include the ROAD CLOSED panel together with either an AHEAD panel (TM1-35B) or a LOCAL TRAFFIC ONLY panel (TM2-41A).
One firm rule comes with it: the LOCAL TRAFFIC ONLY sign shall not be used in conjunction with any regulatory sign, such as NO ENTRY (R2-4), NO LEFT TURN or NO RIGHT TURN. The two messages contradict each other, one invites local traffic in, the other prohibits entry, so the standard does not allow them together.
How is a detour signed from start to finish?
A detour is its own signed route, and AS 1742.3 gives it a family of signs that work as a chain:
| Sign | Where it goes | UAGS panel |
|---|---|---|
| DETOUR AHEAD (T1-6) | Advance warning of a detour bypassing a section of roadway that is not trafficable or under work | Detour Ahead TM1-6A |
| DETOUR directional (T5-1B) | At the point where traffic leaves the normal roadway, showing the direction, usually with DETOUR AHEAD in advance | Left, Right, Straight, U-Turn |
| Reassurance along the route | Detour signs guide and reassure traffic along the detour. In built-up areas the Detour marker (T5-6) is used instead where a full Detour sign could misdirect other road users, and in a multi message frame it runs with the DETOUR panel (TM5-7A) | Detour TM5-7A |
| END DETOUR (T2-23) | Where the detour ends and road users return to their original route. Where it is used, a separate END ROADWORK sign is not necessary | End Detour TM2-23A, TM2-23C |
Intersections within the detour get their own control, with signs such as All Traffic Turn directing the movement through each junction, and the whole route is set out in the traffic guidance scheme before a single frame goes out.
1200x300mm directional panel for the point where traffic leaves the roadway. Right, straight and U-turn versions linked in the table above.
Marks where road users return to their original route, and stands in for END ROADWORK where it is used.
What about side roads?
Where a side road entering the route is closed to all traffic, the SIDE ROAD CLOSED sign (T1-32) shall be used in advance of the intersection, so drivers on the main road are not surprised by a blocked turn. UAGS stocks the Side Road Closed TM1-32A panel, along with the supporting On Side Road TM5-9A and No Through Road panels that round out side street signing.
What are barrier boards and when are they required?
Barrier boards are the physical half of a road closure. AS 1742.3 requires them with the ROAD CLOSED sign, barring access completely, and describes barricades generally as devices used to inhibit access to a work area, erected roughly perpendicular to the direction of traffic at intervals not exceeding 100 metres.
The boards themselves are 150 to 200mm high and no more than 4 metres long, mounted on trestles or fixed posts about 1 metre above the pavement, striped in alternate diagonal black and retroreflective yellow with yellow at each end. The stripes are not decoration: where a board faces traffic, the bars point down toward the side vehicles are required to pass. Two firm rules complete the picture. Barrier boards are not a delineation device, that job belongs to cones, bollards and delineators, and they must never be placed parallel to the direction of traffic, where an end-on strike can turn a board into a spearing hazard. Barricade devices are also subject to the test requirements of AS/NZS 3845.2.
What about lane closures?
Closing a lane rather than the whole road brings in the Lane Status sign (T2-6), which gives advance warning of which lanes are closed or altered, and only that, the standard is explicit that it is not a substitute for properly signing and delineating the closure itself. Built in a multi message frame, an A size panel shows no more than two lanes and a C size panel no more than four, and the sign goes on both sides of a multilane road wherever practical. We cover the sign in detail in our lane status signs guide.
Frequently asked questions
What sign do I need to close a road?
A temporary closure uses the ROAD CLOSED sign (T2-4, or TM2-4 as a corflute panel in a multi message frame) at the position where the roadway is closed, with barrier boards barring access used in conjunction with it, and advance warning signs such as ROAD CLOSED AHEAD before it. The full arrangement for any site comes from the traffic guidance scheme.
Do I need barrier boards with a ROAD CLOSED sign?
Yes. AS 1742.3 says barrier boards completely barring access to the roadway shall be used in conjunction with the ROAD CLOSED sign. The sign tells drivers the road is closed; the boards physically prevent access.
What is the difference between ROAD CLOSED and ROAD CLOSED AHEAD?
ROAD CLOSED AHEAD is the advance warning placed before the closure so traffic can divert early. ROAD CLOSED stands at the closure point itself. A properly signed closure uses both, at different positions.
How do I sign a detour?
As a chain: DETOUR AHEAD in advance, a directional DETOUR sign at the point traffic leaves the roadway, reassurance detour signs or markers along the route, and END DETOUR where road users return to their original route. The route and sign positions come from the traffic guidance scheme.
Can LOCAL TRAFFIC ONLY be used with a NO ENTRY sign?
No. AS 1742.3 says the LOCAL TRAFFIC ONLY sign shall not be used in conjunction with any regulatory sign, including NO ENTRY, NO LEFT TURN and NO RIGHT TURN, because the messages contradict each other.
Do the right signs make a road closure compliant?
No. Signs are one part of a closure. The arrangement, positions, devices and approvals are determined by the traffic management plan, the traffic guidance scheme, site conditions and the relevant road authority's requirements.
Every panel in the closure chain, in stock
Road Closed, Road Closed Ahead, the full detour family and the frames that carry them. Trade pricing available. Pickup from Bayswater North VIC or delivery Australia-wide.
Browse Multi Message Signs →Selection, combination and placement of temporary traffic management signs and devices remain subject to the applicable TMP, TGS, site conditions and relevant authority requirements. This article is general information for the Australian market, not traffic management design advice.