Pavement design article 20140120144156 Resized WEB

The Western Australia Government (WA) in the 2013-17 budget announced $26.9 billion in infrastructure investment over the next four years. Of this amount, it’s expected that more than $8 billion will be spent by Main Roads WA (MRWA) across the state. But with this increased expenditure also comes increased risk for contractors and consultants – how are you impacted?

Pressure for quality performance

There are many risks associated with the design, construction and maintenance of road pavements.

MRWA has existing guidelines and construction specifications. But they don’t cover all performance obligations. More and more, the risk of poor performance is shifting to design and construction (D&C) contractors and their consultants.

Inadequate pavement performance may include:

  • premature pavement defects such as rutting and cracking
  • deflection, curvature and roughness greater than the acceptance limits prescribed by MRWA
  • stripping in asphalt
  • surface distress in concrete pavement

Poor pavement performance can come from pavement materials and construction practice failing to meet design requirements over the life of the road.
As traffic volume and truck-loading weight have increased, new materials such as full depth asphalt and concrete have been applied to support this increased capacity.
However, many of these new materials are yet to be tested for long-term performance and durability. With such a competitive project landscape, many organisations are choosing to take on this risk in order to be competitive - this is creating acute risk for many organisations. 

Coffey’s view

We’ve worked on recent major road projects under the control of MRWA. We’ve witnessed first-hand projects where premature defects have occurred. We’ve also been involved in assessing these defects, identifying why they haven’t performed and developed rehabilitation plans. We’ve learnt a lot.

We believe the risks of using new materials and potential inadequate pavement performance can be managed effectively during the design stage. This may include revisiting asphalt mix design, better pavement type selection and introducing sound design parameters. Although the risk can’t be completely removed, through enhancing your pavement design, the risk can be managed.

How we help

Risk assessment for the design, construction and performance of pavements is essential. Spanning many years, we have experience working with road pavements in WA specifically, and across Australia.

We can assess your risks, and provide a practical and cost-effective approach to help you manage these for your organisation. 

If you’d like more information on this development, please contact me on +61 8 9355 7100 or by email at