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MGS Longspan Question

Description Text

I know that you have crashed tested the MGS without
blockouts successfully.  Can the MGS Long span guardrail be used without
blockouts with back of the posts flush with the face of the hubguard outside
the limits of the RCB? We are using this on a low volume roadway in California.


How much tolerance is there for the hubguard to extend above
the pavement for a long span MGS installation? 


Thank you.



  • Guardrail
Other Keywords Lon Span
Date May 19, 2017


We have not crash tested the MGS Long-Span System without the use of blockouts on the three CRT posts adjacent to the 25-ft span. As such, I would not suggest placing the railing system farther back than was used in the successful MASH crash testing program. As I recall, we did test one of the two MASH tests with the back side aligned with the traffic-side face of the headwall. Still, wood blockouts were used on the front face of the CRT posts. Removal of blockouts would farther locate the vehicle off of the culvert edge, which has not been evaluated.


With regards to non-blocked MGS near MGS Long-Span, general guidance has suggested that the non-blocked MGS could begin one span (6 ft - 3 in.) away from the outermost CRT post as long as sufficient level, or approximately level, terrain exists behind the posts. This guidance has been included in MwRSF Report No. TRP-03-262-12.


Let us know if you have any further questions or comments.

Date May 20, 2017

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