Curved Pathways and Ramps: Understanding AS1428.1:2021 Requirements
Navigating curved walkways and ramps might seem straightforward, but when it comes to accessibility standards, the details matter. The updated AS1428.1:2021 – Design for Access and Mobility provide clearer guidance on applying clear widths to curved pathways, addressing areas of confusion from the previous 2009 edition.
Clause 7.4(f) of AS1428.1:2021 focuses specifically on curved walkways, ramps, and landings. In the earlier AS1428.1-2009 (Clause 10.4), the following requirements were outlined for curved pathways and landings:
- Gradients: Must comply with slope requirements (see Figure 20 in the standard).
- Landings: Must follow Clause 10.8 for dimensions and placement.
- Ramp Measurement: The length of a curved ramp must be measured along its centreline.
- Minimum Clear Width: All curved ramps and walkways must provide a minimum clear width of 1500mm.
- Crossfalls: Any crossfall should be directed toward the centre of curvature.
While comprehensive, these rules led to practical questions:
- What qualifies as a “curved” walkway or ramp? For instance, does a gentle 20-meter radius path need to meet the 1500mm clear width requirement?
- How should a 1000mm straight walkway transition into a 1500mm curved walkway?
Clarifications in AS1428.1:2021
The 2021 update has refined the definition of a curved ramp:
- Curved ramps are now defined by an inside radius of 5 meters or less.
- Ramps with an internal radius greater than 5 meters are not required to provide 1500mm clear width and may maintain the standard minimum of 1000mm.
- Junctions between straight and curved sections:
- Where a straight walkway or ramp meets a curved section, a 1500mm long straight landing must be provided.
- This landing should intersect the straight and curved sections along their centrelines.
- The change in width from 1000mm (straight component) to 1500mm (curved component) is accommodated entirely within this 1500mm landing length.
For designers, builders, and accessibility consultants, these clarifications remove ambiguity and make it easier to comply with accessibility standards without over-engineering. Understanding the exact definition of a curved ramp ensures that wider widths are applied only where necessary, while junction landings provide safe, navigable transitions for all users.
By following the updated guidance in AS1428.1:2021, we can create pathways that are not only technically compliant but genuinely accessible and user-friendly.