Components, systems and materials › Road furniture and safety › Wire rope safety barrier
Wire rope safety barrier
What it is
A wire rope safety barrier is a flexible system of three or four tensioned steel ropes on light posts that catches vehicles and slows them over a long deflection.
Where it is used
Wide medians and roadsides with space behind the barrier, especially on rural high-speed roads to prevent cross-median crashes.
How it works
The ropes deflect on impact and engage the vehicle, spreading forces and decelerating it gently, which lowers occupant injury. Posts break or bend away; tension is held by end anchors so the ropes return to position after minor hits.
Types
- Three-rope and four-rope systems
- high-tension and low-tension systems
- socketed and driven posts
Materials
Galvanised steel wire ropes, light steel posts in sockets, end anchor blocks, tensioners and turnbuckles.
The main parameter is working width, which can be large, so there must be clear space behind. Tension is set for the temperature range. Posts are spaced as per the tested system. Anchors are designed for full rope tension. Sharp curves need special treatment.
Installation and QA steps
- Cast end anchors and post sockets.
- Install posts.
- String and tension ropes to the temperature chart.
- Fit terminals and delineators.
- Re-tension and replace posts after impacts.
- Loss of tension after hits or temperature changes
- insufficient space behind for deflection
- damaged posts not replaced
- motorcyclist concerns where not mitigated
Codes cited
- IRC:119 (India): Guidelines for traffic safety barriers.
- EN 1317 (series) (Europe): Road restraint systems: performance classes and impact test methods.
- AASHTO MASH (USA): Manual for Assessing Safety Hardware: crash test procedures for roadside hardware.
Cited by number only. We do not reproduce code text, tables or figures.
Related
Generic description for education. We do not name, endorse or compare manufacturers or products.
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