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Implementation of MASH Ali Hangul, P.E. Tennessee Department of Transportation. Guardrail Standards. At The beginning of MASH. TXDOT research at TTI passed MASH using 36” barrier height. 31” w-beam GR with 8 blackout tested for a small vehicle by TTI for TXDOT.
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Implementation of MASH Ali Hangul, P.E. Tennessee Department of Transportation
TXDOT research at TTI passed MASH using 36” barrier height 31” w-beam GR with 8 blackout tested for a small vehicle by TTI for TXDOT
31” w-beam GR with 8 blackout tested for a small vehicle by TTI for TXDOT • 31” w-beam GR in slope TTI completed for Roadside Safety Pooled Fund 6:1 6’ post 4:1 7’ post 3:1 8’ post 2:1 9’ post 1:1 11’ post Pooled Fund Study : “Placement of Guardrail on Slopes” Phase III: New Guardrail Design for Placement on 1H:1V Slopes
TL-3 Tangential GR end terminals (Proprietary items) • Two models reevaluated per NCHRP 350 for 31” (Confusing for users) • One new design evaluated per MASH for 31” (One point to consider, MASH does not require 31” installation height) • Waiting for two additional manufacturers to have their products being evaluated. Than the Department can adopedMASH exclusively. Terminals
Recently TTI completed a study for TX DOT Downstream End Terminals
TDOT Standard Initial detail
Currently no MASH evaluation (TL-2) is proposed for slotted flared terminal
31”Bridge parapet transition Current Issue • Working processDesign and NCHRP Report 350 Finite Element Analysis of Stacked W-Beam Transition for 31-inch Guardrail (601721)
Currently the only alternative is adopting thrie beam transition detail developed by TXDOT
Simulation completed for NCHRP 350 TL-3 at 31” further evaluation is needed for MASH
Tangential Guardrail End TerminalsInitial revision did not address the special GR length as well as payment length
Thank you ALI R. HANGUL P.E., CPESC| Assistant Director Headquarters Roadway Design and Office of Aerial Surveys James K. Polk Bldg, 13th Floor, 505 Deaderick St., Nashville, TN 37243 Phone No. 615-741-0840 ali.hangul@tn.gov tn.gov/tdot