TTI Research Supervisor: Nathan D. Schulz, Ph. D.
Associate Research Scientist
Texas A&M Transportation Institute
Texas A&M University System
TAMU 3135,
College Station, Texas, 77843-3135
(979) 317-2694 [email protected]
Pooled Fund Technical Representative: Todd Ingarra
Transportation Engineer 3
State of Connecticut
Department of Transportation
Engineering Services/ Facilites & Transit
(860) 594-32892 [email protected]
ABSTRACT
The Merritt Parkway Guiderail was previously testing and evaluated according to guidelines included in the second edition of the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) (1). The system was found to be unsatisfactory for Test Level 3 (TL-3).
Finite element computer simulations were used to evaluate design concepts developed to improve the crashworthy performance of the Merritt Parkway Guiderail. A design which incorporated a 1-inch-thick splice plate was evaluated according to MASH TL-3. The system did not meet the MASH TL-3 evaluation criteria. A second design was tested and evaluated that incorporated a 1-inch-thick splice plate and joints at midspan. This system was successful in meeting the MASH TL-3 criteria. The satisfactory performance of the system was based upon the presence of a 4-inch curb. The design was also tested without a curb but did not meet the MASH TL-3 criteria. Another design was evaluated with full-scale crash testing that incorporated 1-inch-thick splice plates, joints at midspan, and a rubrail. This system was successful in meeting the MASH TL-3 criteria.
Two designs for the Merrit Parkway Guiderail met the performance criteria for MASH TL-3 Longitudinal Barrier. One design had a 4-inch curb and incorporated 1-inch-thick splice plates and joints at midspan. The second design did not have a curb and incorporated 1-inch-thick splice plates, joints at midspan, and a rubrail.
