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MGS with Curb and Omitted Post: Evaluation to MASH 2016 Test Designation No. 3-10




Scott Rosenbaugh, Cody Stolle, Kellon Ronspies




The use of curbs along roads is often required for certain functions such as drainage control, right-of-way reduction and sidewalk separation. However, curbs along roadways can adversely affect the interaction of errant vehicles with roadside barriers. When curbs are placed near guardrail systems, the propensity for vehicle underride, override, and instability increases. Additionally, the presence of drainage features often prevent the placement of guardrail posts, thus requiring a post to be omitted. Thus, the test installation evaluated herein consisted of the Midwest Guardrail System (MGS) placed with the front face of the guardrail located 6 in. (152 mm) behind a 6-in. (152-mm) tall, AASHTO Type B curb and one post omitted near the middle of the system, resulting in a 12.5-ft (3.8 m) span between two posts. Test no. MGSCO-1 was conducted on standard MGS with the rail mounted 32 in. (813 mm) above the roadway. During test no. MGSCO-1, the W-beam ruptured at the splice located within the unsupported span, and the test vehicle penetrated behind the system and eventually rolled over. To strengthen the system, 37.5 ft (11.4 m) of nested rail was recommended for placement around the location of the omitted post. During test no. MGSCO-2, the vehicle was successfully contained and redirected without any evidence of rail tearing. The vehicle remained stable, and all of the vehicle decelerations met the allowable limits. Thus, test MGSCO-2 passed the safety criteria of MASH 2016 test designation no. 3-10. Additional testing according to MASH 2016 test designation no. 3-11 is recommended to complete the MASH 2016 testing matrix prior to the implementation of the system on roadways.


Highway Safety, Crash Test, Roadside Appurtenances, Compliance Test, MASH 2016, Test Level 3, Curb, Guardrail, Omitted Post, Nested W-Beam, MGS

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