Department of State GrowthTransport

Infrastructure Investment Plan Stream 1

Sustainable maintenance

The challenge

To sustainably deliver expected customer levels of service, road and bridge infrastructure must be maintained and replaced at an optimum rate otherwise maintenance costs rise and average asset condition, safety and functionality is reduced.

The average age of state roads and bridges will continue to increase and so therefore will the cost of asset maintenance and replacement.

The age of state road bridges

The age of state road bridges.  Lifespans of bridges can vary dramatically but are typically expected to last between 70 and 100 years and is primarily dependent upon the type of construction, effectiveness of periodic maintenance and environmental factors.  The average age of state road bridges is increasing and the replacement of bridges will increasingly need to be prioritised based on strategic considerations.

The age of state road pavements

The age of state road pavements shown in terms of length of roads at varying ages.  Road pavements typically have an average age of between 40 and 60 years depending upon the history of the road and heavy vehicle utilisation.  The average age of state roads is increasing, meaning the cost of maintenance is increasing and there will a need for increased road pavement replacements in the future.

The length of state roads, and the amount of assets being managed is increasing, for example lane length has increased by eight per cent over the last 20 years, meaning long-term maintenance and replacement costs to deliver consistent levels of services continues to increase.

Increase in the length of the State Road Network since 1998

Increase in the length of the State Road Network since 1998 as measured in lane kilometres (nine per cent).  The increase in assets being managed has obvious implications for maintenance expenditure.

New infrastructure assets and upgrades come with ongoing maintenance and ownership costs which are typically in the order of five times as much as the cost of construction over the life of the asset.

Customer level of service expectations across the spectrum of state road services are generally tending to increase, which places increasing pressure on maintenance budgets.

Investment Plan

State road maintenance and replacement will be funded to deliver consistent and increasingly defined customer levels of service, including:

  • replacement of prioritised bridges at the end of their economic life, excluding upgrade projects and bridge strengthening
  • replacement of approximately 27 identified lengths of road pavement at the end of their economic life, excluding road pavement replaced in the course of road upgrade projects
  • a consistent investment profile over 10 years on replacement of sealed road surfaces and road linemarking
  • ongoing investment on road, bridge and roadside maintenance including emergency response services.

View the program details (PDF)

For information about the Infrastructure Investment Plan Streams, please refer to the following: