AS 1742: Road Marking Standards Guide

A contractor marked a private road in a business park using yellow centre lines. The council inspector failed the work immediately. In Australia, yellow centre lines aren't used—that's a US convention. AS 1742 specifies white for all lane delineation.

AS 1742 is the comprehensive Australian Standard series covering road marking. While primarily written for public roads, it's widely referenced for private roads, carparks, and any traffic areas where consistent marking helps users navigate safely.

The AS 1742 Series Structure

AS 1742 is a multi-part series covering different aspects of traffic control. The part most relevant to line marking is Part 2.

Key Parts:

AS 1742.1: General introduction and index
AS 1742.2: Traffic control devices for general use (pavement markings)
AS 1742.3: Traffic control for works on roads
AS 1742.10: Pedestrian control and protection
AS 1742.11: Parking controls

Line Types and Meanings

AS 1742.2 defines specific line types with distinct meanings that drivers are trained to recognise.

Centre Lines:

Single broken white line: Overtaking permitted with caution
Single continuous white line: No overtaking (single direction)
Double continuous white lines: No overtaking (both directions)
Broken line alongside continuous: Overtaking permitted from broken side only

Edge Lines:

Continuous white edge line: Delineates road edge
Yellow edge line: No stopping zone

Lane Lines:

Broken white lines: Lane guidance, lane changing permitted
Continuous white lines: Lane change not permitted (turn lanes, merges)

Colour Specifications

Australian road marking uses a limited colour palette with specific meanings.

White:

Used for all lane delineation, centre lines, edge lines, stop lines, give way lines, pedestrian crossings, and general traffic guidance. White is the default colour for road marking.

Yellow:

Reserved for parking restrictions: no stopping zones, no parking zones, loading zones, taxi zones, and bus zones. Yellow indicates parking control rather than traffic flow.

Blue:

Used exclusively for accessible parking bays—the International Symbol of Access on blue background.

Line Dimensions

AS 1742.2 specifies dimensions for various line types.

Standard Line Widths:

Centre lines: 80-150mm (typically 100mm)
Edge lines: 80-150mm (typically 100mm)
Lane lines: 80-150mm (typically 100mm)
Stop lines: 200-450mm (typically 300mm)
Give way lines: 300-450mm (broken line)

Broken Line Patterns:

Standard broken centre line: 3m mark, 9m gap (1:3 ratio)
Continuity lines (approaching hazards): 1m mark, 1m gap
Lane lines: 1m mark, 3m gap

Pavement Arrows

Directional arrows follow specific designs defined in AS 1742.2.

Arrow Types:

Straight ahead arrow
Left turn arrow
Right turn arrow
Combined straight/turn arrows
Merge arrows

Standard arrow length for roads is 6m, with smaller variants (3m, 1.5m) for lower-speed environments like carparks.

Application to Private Roads and Carparks

While AS 1742 is written for public roads, applying its principles to private roads and carparks ensures consistency and user familiarity.

Where AS 1742 Applies to Private Areas:

Private roads with public access (shopping centres, business parks)
Carpark driveways and circulation routes
Loading dock access roads
Industrial estate internal roads

Request road marking to AS 1742 standards

Frequently Asked Questions

Why doesn't Australia use yellow centre lines like the US?

Australia follows the Vienna Convention on Road Signs and Signals, which uses white for traffic flow markings. Yellow is reserved for parking restrictions, making the system consistent and preventing confusion.

Can I use different colours for decorative effect?

For traffic control markings, no. Using non-standard colours creates confusion and potential liability. Decorative coloured surfaces are possible in non-traffic areas, but any traffic marking should follow AS 1742 colours.

Do carparks need to follow AS 1742 exactly?

Carparks primarily follow AS/NZS 2890.1 for parking bays and AS 1742 principles for circulation routes. Scaled-down versions of AS 1742 arrows and markings are appropriate for lower-speed carpark environments.

AS 1742: Road Marking Standards Guide | Line Marking Australia Blog