I've been working on developing WisDOT's standard detail drawings for the MGS system and I have a question. I was reviewing MwRSF's crash test report, "Development and Evaluation of the Midwest Guardrail Systems (MGS) Placed Adjacent to a 2:1 fill Slope" (TRP-03-185-10).
In this report, MGS with standard post spacing, 6' 4" post embedment was tested at two rail heights (27 ¾" and 31"). The 31" height passed MASH, but the 27 ¾" rail height failed MASH.
What would be the lower height limit for MGS on a 2:1 slope? What modifications should a designer do a MGS system with standard post spacing and 6'4" of embedment that has had the 31" rail mounting height lessened by overlays (e.g. install a normal length post at the midspan)?
Some parts of this site work best with JavaScript enabled.