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A detail
was given to us by a contractor wanting to use ADOT’s front face barrier
transition for adding light poles on top of barrier in lieu of MoDOT’s standard
where no transition on front face is required since it (ADOT’s) will allow for
slip forming the barrier.

Our
barrier will be 42” tall (Type D single sloped 11%) without a light pedestal
added.

Is
ADOT’s detail with 5’ front face transitions from a sloped face to a vertical
face at the light pole using MoDOT’s 42” barrier without a light pedestal is an
acceptable detail and if not how can we make it an acceptable detail?

1^st
sheet of attachment – ADOT’s detail with 33” barrier and top mounted pedestal

2^nd
sheet of attachment – MoDOT’s standard lighting blister

I would
appreciate your comments. Thx.

For lateral tapers on the front face of concrete barriers, we have started to suggest the use of a 1:10 (lateral to longitudinal) when the shape transition extends over a larger vertical footprint. Note that this suggestion was solely based on LS-DYNA simulations involving vehicle impacts into a lateral shape transitions on rigid concrete buttresses. Full-scale crash testing has not been performed to confirm nor modify these simulation findings.

Previously, MwRSF conducted limited crash testing on luminaire poles attached to 32-in. tall single-slope parapets under TL-4 impacts using NCHRP Report No. 350. A link to the report and crash videos is provided below:

https://mwrsf.unl.edu/reportresult.php?reportId=104&search-textbox=zoi

Are you considering the configuration under MASH TL-3 or TL-4? Also, I would need to see the CAD details to further comment (not attached in prior email). Thanks!