G9 Thriebeam Guardrail Barrier

The G9 Thriebeam road safety barrier has a greater profile which is better adept to protect motorists from any danger or hazard that may be close to the verge of the road.  It is positioned higher than a standard w-beam would traditional be placed and delivers the highest levels of performance, specifically were retaining large vehicles are concerned.

Roadside barriers have been developed over the years to safely redirect vehicles that leave the roadway. Many different rigid, semi-rigid and flexible designs for roadside barriers have now evolved. The Thriebeam system consists of a semi-rigid steel beam rail, similar to the w-beam but with an extra corrugation. Supported on steel posts with end treatments and transitions of various designs using similar materials.

An important attribute of the Thriebeam guardrail is its high level of performance, especially for larger vehicles. Due to the greater height of the rail face, Thriebeam guardrail provides reduced deflection and improved resistance to vehicle vaulting or under running. The reduced dynamic deflection and maintenance demand makes the Thriebeam guardrail ideally suited for major facilities carrying a high volume of high-speed traffic. The Thriebeam guardrail should also be used in transition from the Flexbeam guardrail for more rigid barriers. This significantly reduces the deflection of the barrier system at the transition to the rigid barrier.

Another important note to observe is regarding transitions from w-beam to the thriebeam guard rail.  General applications of this can be seen on bridge approaches as they provide an effective changeover from a rigid to a semi-rigid barrier.  The robustness of the thriebeam road safety barrier reduces deflections which in turn, lessens the chance of vehicle pocketing.

  • OPTIMAL PERFORMANCE – High performance to retain larger vehicles
  • SAFER – Less deflection and enhanced resistance to under running or vaulting
  • COMPLIANCE STANDARD – The G9 Thriebeam performs to NCHRP-350 TL3 standards
  • LOW DEFLECTION – Reduces the clear zone required. Great for locations with hazards close to the barrier.

G9 Thriebeam Guardrail Barrier


Post Length:2,100mm
Post Mass:27.6kg
System Mass:37.75kg per meter
Rail height above ground:805mm
Post height above ground:805mm
Post Spacing:2,000mm
System Width:385mm
Crash Rating:NCHRP-350 TL3
Crash Test Deflection:0.6m
Surface Treatment:Galvanized to AS/NZS 4680 after fabrication

G9 Thriebeam Guardrail Barrier