Thursday, 20 August 2026
Austroads has strengthened guidance on the selection of batter slopes, providing road agencies with updated advice to support safe, resilient and sustainable roadside design across a range of terrain and operating conditions.
Batter slopes are a fundamental component of road design. They influence how vehicles behave if they leave the roadway, affect long-term maintenance requirements, contribute to slope stability and erosion control, and play an important role in landscaping and the visual integration of road infrastructure.
A review of Australian, New Zealand and international guidance found differing approaches to batter slope selection, particularly in how factors such as motorist safety, maintenance requirements and slope stability are prioritised. The findings informed updates to the Austroads Guide to Road Design Parts 3 and 6, supporting a more consistent approach across road design guidance.
The updated guidance recommends that batter slope selection considers a broader range of factors, including motorist safety, safe and efficient maintenance practices, landscaping objectives, erosion control and whole-of-life asset performance, rather than focusing primarily on slope stability.
Austroads Road Safety and Design Program Manager Michael Nieuwesteeg said batter slope design can significantly influence the long-term performance and safety of a road corridor.
“Roadside slopes are often assessed through the lens of geotechnical stability, but that is only one part of the picture. Decisions made during design can also affect how safely a vehicle can recover after leaving the road, how easily infrastructure can be maintained and how effectively erosion can be managed.”
The research identified that flatter batter slopes can improve safety outcomes, support maintenance activities and assist with vegetation establishment and erosion management. It also highlighted opportunities to better connect batter slope guidance with existing Austroads information on drainage and erosion control.
Michael said the updated guidance gives practitioners a clearer framework for navigating competing design considerations.
“There is rarely a single factor that determines the most appropriate batter slope. This guidance helps designers evaluate safety, maintenance, stability and environmental outcomes together, leading to more practical and sustainable solutions.”
The findings provide road agencies, designers and consultants with a stronger evidence base for selecting batter slopes that perform effectively throughout the life of a road asset.
Download Updating Batter Slope Guidance in Austroads Guide to Road Design.
View the recording of our webinar exploring the report's findings, recommendations and their implications for road design, standards development and project delivery: Update to the Austroads Guide to Road Design: Addressing identified gaps and inconsistencies – Session 1