W Beam Guardrail

W Beam Guardrail

Compliance to State Road Authority Specifications.

Also known as G4 W-Beam, the Australian public domain w-beam guardrail barrier with C-posts is manufactured in accordance with state road authority specifications. It is adopted for use in NSW, Queensland, South Australia and Western Australia. The system comprises steel C-posts that support a w-beam rail element that is blocked out from the posts. U-posts are adopted for use in Victoria and Tasmania.

The use of blocking pieces minimises vehicle snagging on the posts and reduces the potential for the vehicle to vault over the barrier by maintaining rail height during the initial stages of impact.

W-Beam Guardrail with C-Posts is compliant to AS/NZS 3845 and is deemed to comply with the requirements of NCHRP Report 350 Test Level 3.


    • High visibility creates driver confidence.
    • The post and block design reduces wheel snagging and the consequential effects of vaulting or rollover.
    • Performs well on the outside of curves, even those of relatively small radius, as the concave shape (in plan view) supports the development of tension in the rail.
    • Can be used in verge or median locations.
    • Compliant to AS/NSZ 3845.
    • Hot dip galvanised in accordance with AS/NZS 4680.
    • Standard Post spacing – 2m.
    • Height to top of rail;
      • 710mm (SA & NSW).
      • 730mm (Qld & WA).
    • Dynamic deflection at 2.0m post spacing – 1.0m^ (2000kg vehicle at 100km/h and 25°).
    • Recommended minimum Length –30m.^^
    • Where a kerb exists at the edge of the road, it is recommended that the barrier be placed within 200mm of the face of the kerb or a distance behind it to ensure that impacting vehicles do not vault over the barrier.^^
    • Recommended minimum distance between the rear of the system and the hinge point of the batter – 600mm.^^