Impact Performance Evaluation of Ezy-Guard High Speed Guardrail System

The performance of untested steel guardrail systems has been observed and commented on by experts in the field of the Middle East, with common observations showing that impacting vehicles have "splintered" W Beam Guardrails. This risk can be mitigated by using a system that has been tested to the standard (US NCHRP350 or MASH) such as Ezy-Guard.

Ezy-Guard and the untested system were installed on a new road at the same time and the following observations are made during the field trip:

1.Untested system

Several corrugated guardrail collision points were observed where the angle and level of impact was less severe and the guardrail was damaged and redirected the vehicle. However, where the angle was significantly more severe, short lengths of guardrail damage were noted, but the W Beam Guardrail cracked and failed to accommodate the vehicle.

Description of the above photograph.

(1) Scratches are observed at the point of impact on the highway guardrail beam.

(2) The damaged part of the highway guardrail beam is completely removed.

(3) The bent highway guardrail beam is partially split.

(4) Adjacent posts are only slightly deformed near the point of impact.

Summary: In this example, the spacing is one post every 4 meters, and the point of collision indicates that the post was deformed very little and therefore absorbed the energy. The severe damage to the waveform guardrail beam suggests that it has been subjected to excessive forces, causing the beam to split.

Before and after the point of collision, the post is too rigid, combined with the large post spacing, which can result in the w beam being subjected to a large redirection angle through interaction with the vehicle. In a heavier collision with large vehicles, this can put excessive pressure on the w beam and lead to failure.

Ezy-Guard highway guardrail system

Several collision points were observed and successfully controlled.

Description of the above photograph.

(1) Possible point of impact and approximate angle according to tire marks.

(2) Posts are deformed and deflected before and after the point of impact.

(3) Description of the situation behind a highway guardrail.

Deformed posts absorb energy and provide lateral resistance. W beams were not torn, but lay on the sand because there were no longer posts to support them after the impact.

Summary: Ezy-Guard posts, installed every 2 meters, have been designed and tested to deform on impact, allowing the w beam to smoothly redirect the impacting vehicle without significantly increasing the forces on the w beam. The deformed posts continue to provide lateral resistance through the sliding frame without subjecting the w beam to forces that significantly increase the angle of interaction or attempt to pull the w beam down as the post rotates or deforms in the soil. W beams can smoothly redirect a vehicle back onto the road and control collisions as seen from field tests.