Flex-Rail® W-Beam

Semi-rigid W shape section galvanised steel highway barrier.

Flex-Rail® W-beam is the most common roadside crash barrier in use in New Zealand.

The current W-beam barrier shape became the standard in the USA in the 1950s and was first introduced into New Zealand in the early 1960s, manufacture of Highway guardrails in New Zealand began in the early 1970s.

CSP supplies 12 gauge Highway Flex-Rail® with a base metal thickness (BMT) of 2.7mm and a 3.81m effective length.



Flex-Rail® is roll formed from coil steel and sheared to length. It is then punched, slotted and hot dip galvanised in accordance with AASHTO Specification M180 and AS/NZS 3845.1:2015.

Flex-Rail® is available ex-stock in standard effective lengths of 3.81 metres and 1.905 metres for Highway rail.

Curved Flex-Rail™

The standard straight section will align to give a smooth transition on curves with a radius greater than 45m. Pre-curved Flex-Rail® is required for tighter radii and may be curved to traffic face concave or convex - see table on Flex-Rail Brochure.


Currently no specifications available


Flex-Rail® W Beam complies with the requirements of:

  • AS/NZS 3845.1:2015 - Road safety barrier systems
  • NZ Transport Agency specifications M/23 and M/17P.