Barrier Line Marking

Document No:  D18#15606
Revision:  1A
Date amended:  10-Jan-2018

​The information below is intended to reflect the preferred practice of Main Roads Western Australia ("Main Roads"). Main Roads reserves the right to update this information at any time without notice.

If you have any questions or comments on the Barrier Line Marking Assessment Guideline please contact Ron Koorengevel by e-mail or on (08) 9323 4704. 

If you have any questions or comments on Barrier Line Visibility Report please contact Dave Nicholls by e-mail or on (08) 9323 4325.

To the extent permitted by law, Main Roads, its employees, agents, authors and contributors are not liable for any loss resulting from any action taken or reliance made by you on the information herein displayed.

Revision Register

Revision NumberClause NumberDescription of RevisionDate
1All Barrier Line Marking Guideline Developed and Approved.27-Sep-2016
​1AAll​​Barrier Line Marking Assessment document added.​10-Jan-2018


Table of Content

Barrier Line Marking​ Assessment Guideline

Main Roads has developed a Barrier Line Marking Assessment Guideline to assist with line marking design.

Barrier lines are a subset of longitudinal lines as they separate opposing directions of traffic.  They are provided where it is necessary to prohibit drivers from travelling to the right of a longitudinal line in order to overtake other vehicles.  They may be installed on two lane two way roads where the sealed pavement widths meet the requirements of AS 1742.2 Section 4.2 Pavement Markings and Delineation and where traffic volumes meet the requirements of AS 1742.2 Section 5.3 Longitudinal lines, but where barrier lines are necessary because of sight distance limitations.

A barrier line is a dividing line that replaces the single broken separation line to prohibit crossing movements from one or both directions. This guideline deals with the methodology for establishing unbroken separation/single barrier line, double one way and double two way barrier line markings and their setting out.

Barrier Line Marking Assessment


Barrier Line Marking​ Visibility Report

Main Roads has developed an excel spreadsheet that reads in a MX visibility report (example provided below) then calculates and displays where overtaking barrier line marking should be provided.

The start and end chainages are calculated based on the process defined in Australian Standards AS1742.2

An example of the drawing presentation based on the output can be found in drawing 200331-0033.

NOTE:  Barrier line marking should be verified on site in accordance with AS1742.2

Image: word-icon.GIF  Project Instructions and Workflow

Image: pspad icon.GIF MX Visibility Report (input file)

Image: excel-icon.PNG Barrier Line Spreadsheet