TTI Research Supervisor:
Chiara Silvestri Dobrovolny, Ph.D.
Texas A&M Transportation Institute
College Station, Texas 77843-3135
(979) 317-2687 [email protected]
Pooled Fund Technical Representative:
State of Connecticut
Department of Transportation
2800 Berlin Turnpike
Newington, CT 06131-7546
(860) 594-3288 [email protected]
With the adoption of the AASHTO/FHWA Joint Implementation Agreement for Manual for Assessing Safety Hardware (MASH) in 2015, originally all transition systems for projects on the National Highway System advertised for construction after December 31, 2019 must have been evaluated using the 2016 edition of MASH. At a later date, the original agreement was modified to allow States to specify MASH 2009-compliance of NCHRP Report 350-compliant devices for cases where the State is awaiting completion of MASH-2016 testing for a specific device, among other limited situations.Those transitions that have not been evaluated in accordance with MASH by that time will not be allowed for use on the NHS. In order to comply with this requirement, Connecticut Department of Transportation (CTDOT) proposed to review and crash test a guardrail transition from a 32-inch weak post guardrail system to the 31-inch strong post MGS (with 8-inch blockouts) according to the new MASH requirements.
The research objectives were to:
Develop a design for a guardrail transition from a 32-inch weak post guardrail system to the 31‑inch strong post MGS (with 8-inch wood blockouts),
Perform full-scale MASH Tests 3-21 and 3-20 on the proposed transition system, and
Evaluate the performance of the proposed transition system per required MASH evaluation criteria.
This report provides details of a guardrail transition from a 32-inch MGS weak post system to the MGS strong post system, detailed documentation of the crash tests and results, and an assessment of the performance of the transition for MASH Test Level 3 (TL-3) transition evaluation criteria.
The guardrail transition from a 32-inch MGS weak post system to the MGS strong post system met the performance criteria for a MASH TL-3 transition.