MRWA Supplement to Austroads Guide to Road Design - Part 2

Document No:  D17#492177
Revision:  2B
Date amended:  03-Jul-2020

Image: orange line.RCN-D13^23151823.GIFThe 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 please contact Guillaume Willemsen by e-mail or on (08) 9323 5879.

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


Ed/Version Number Clause Number Description of Revision Date



Guideline Developed. 09-Dec-2011 
​1A​All​Contact person changed to Steve Curgenven​12-Jul-2016
​2​All​Guideline Reviewed.​26-Jun-2017
​2AAll​​Document hierarchy clarified.​07-Feb-2019
​2BHeader​​Contact Person Changed​03-Jul-2020


Table of Content

MRWA Supplement to Austroads Guide to Road Design -

Part 2: Design Considerations

This Supplement has been developed to be read as a supplement to the Austroads Guide to Road Design (GRD) Part 2: Design Considerations (2015), a copy of which can be purchased via the Austroads website.

In Western Australia, Main Roads' policies, guidelines and standards take precedence over Austroads Guides and Standards Australia Standards. National Guides and Standards take precedence over International Guides and Standards, unless specifically stated otherwise.

This Supplement has the same structure as the equivalent Austroads Guide and only additional requirements, clarifications, or practices different from Austroads appear. Where appropriate, this Supplement may also contain additional sections and figures not covered by Austroads, but the numbering sequence found in the Austroads Guide remains. Figures and tables in this Supplement replace those with the same figure or table number in the equivalent Austroads Guide.


Main Roads has no supplementary comments for this section.



2.2 Normal Design Domain

In Western Australia Main Roads Supplement to Austroads GRD Part 3: Geometric Design is used as the primary guide for determining the road cross section, including lane widths for the State Road Network.




Refer to MRWA Guideline Document 'Climate Change' - Document No. D10#97260 for design consideration of runoff, rainfall and temperature.



To the main factors in intersection safety, add:

  • Cycling / pedestrian facilities.


Add reference to the US Highway Capacity Manual (Transportation Research Board 2000).