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Is there guidance for clearance behind the MGS for hardware that has a breakaway base/devices such as light poles or ground mounted signs?

Have any of these devices been tested with the MGS?

On many locations along the IL Tollway the typical section consists of a v-shaped gutter at the edge of outside shoulder, a noise abatement wall that is 5' from the back of gutter.  The guardrail post is set back 6" from the back of gutter, so the distance from the back of post to face of noise wall is 4'.  This 4' space is where light poles and single post ground mounted signs are placed.  If the light pole is centered in the 4' space, the distance from the back of guardrail post to near edge of light pole is approx. 1'-7".  This is obviously less than the 28" minimum clearance distance recommended in the MGS documentation.

There exists guidance for use in placing the MGS in front of various obstacles. In the absence of crash testing with poles, trees, supports, etc., it would be recommended that the Working Widths be used. The working width is measured from the original front face of the barrier system. I have enclosed a table with available working widths from the MwRSF crash testing programs.

If pole placement is desired within the published WW values, then full-scale crash testing would be necessary to verify acceptable safety performance with the alternative pole placement.

A research report published in 2017 evaluated a luminaire placed 20 in. behind the back side of the posts of a standard MGS system. Two full-scale crash tests were performed, according to MASH Test Designations 3-10 and 3-11. For the small car test, the rail height was 32 in. and the small car was smoothly and safely redirected without snagging on the luminaire pole. For the pickup truck test, the rail height was 31 in. and the vehicle impacted the guardrail and the luminaire pole, fracturing the frangible transformer base and releasing the luminaire. Crash test results were determined to be satisfactory. Results of the study are documented here:

https://mwrsf.unl.edu/reportResult.php?reportId=336