Thrie-Beam is tested and accepted to NCHRP350 Test Level 3 (TL-3) with timber posts and blockouts and NCHRP350 Test Level 4 (TL-4) with "I" section steel posts and modified steel blockouts.
CSP supplies Thrie-Beam guardrail with a base metal thickness (BMT) of 2.7mm and in standard net lengths of 4 metres with post spacing at 1m centres.