View Q&A

We found this weak post guardrail approved on the FHWA web site & plan to use it soon.

http://www.aashtotf13.org/Files/Drawings/sgr02a.pdf

With the design showing washers in front of the w-beam should we build as is?

Now with the 31" MGS passed without blockouts we will switch to that in the future.

I am aware that this TL-2 weak-post, W-beam guardrail system was developed and successfully crash tested with a small, thin square washer placed on the front face of the rail. I recall that a smaller hex head bolt was also used with this system to attach the rail to the posts and allow for the rail to easily release away from the posts due to bolt fracture. The version noted below in the link is shown as a TL-2 barrier. However, I recall other modifications being incorporated into the system which resulted in acceptable safety performance under TL-3 within a study conducted for PennDOT. I have attached a draft copy of the TRB paper on this topic. I will see if I can obtain an electronic version of the final paper.