TTI Research Supervisor: Sun Hee Park, Ph.D. Associate Research Scientist Texas A&M Transportation Institute TAMU 3135 College Station, Texas 77843-3135 (979) 317-2688 [email protected]
Pooled Fund Technical Representative: Tim Moeckel Roadside Safety Engineer WSDOT Development Division Washington State Department of Transportation P.O. Box 47329 Olympia, WA 98504-7246 (360) 704-6377 [email protected]
ABSTRACT
The purpose of this project was to determine the steepest allowable flare rate meeting the Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3) for the Midwest Guardrail System (MGS) using finite element (FE) analysis and full-scale crash tests. Based on the FE impact analysis from the Phase 1 project, a 21:1 flare rate was recommended for the MGS. The performance of the 21:1 Flared MGS was assessed according to the safety-performance evaluation guidelines included in the second edition of the American Association of State Highway and Transportation Officials (AASHTO) MASH. The crash tests were performed in accordance with MASH TL-3:
MASH Test 3-10: An 1100C vehicle weighing 2420 lb impacting the Longitudinal Barrier while travelling at 62 mi/h and 25 degrees.
MASH Test 3-11: A 2270P vehicle weighing 5000 lb impacting the Longitudinal Barrier while traveling at 62 mi/h and 25 degrees.
Test 3-10 on 21:1 Flared MGS met the performance criteria for MASH TL-3 Longitudinal Barrier. However, Test 3-11 on 21:1 Flared MGS did not meet the criteria due to rail rupture. Consequently, an additional Test 3-11 on 25:1 Flared MGS was performed but did not meet MASH performance criteria due to rail rupture. Finally, additional 3-11 testing was performed on the 38:1 and 30:1 Flared MGS, both of which met MASH TL-3 performance criteria for Longitudinal Barriers. This report provides results for the impact simulations, details of the tested systems, the crash tests and results, and the performance assessment of the 21:1, 25:1, 38:1, and 30:1 Flared MGS for MASH TL-3 Longitudinal Barrier evaluation criteria.
