Tennessee Major Highway Project Gets Approved Safety Boost

Trinity Highway News | April 2016

In January 2016, the Federal Highway Administration (FHWA) encouraged implementation of Manual for Assessing Safety Hardware (MASH) roadside products by announcing sunset dates for NCHRP Report 350 products. Contractors in Tennessee were encouraged to consider MASH crash cushions along with 350 other systems last July in Lawrence County on Project NH-15 (180). This 5.7-mile paving project on U.S. 64 involved a bypass for S.R. 15, base, paving, guardrail and markings. Average daily traffic on this 70-mph roadway is currently 4,600, and is expected to increase to 5,500 by 2034.

According to Ali Hangul, P.E., CPESC, assistant director of the Tennessee Department of Transportation (TDOT), “Our top priority is the safety of the motoring public. Immediately after MASH was published, the design division began evaluating how to implement MASH. The division is continuously updating the TDOT Qualified Products Lists (QPL) to include manufacturers that have tested their safety hardware under MASH criteria and have received an eligibility letter from the FHWA. The QuadGuard M10 MASH-Complaint Crash Cushion was the first attenuator product line to complete testing under MASH criteria. As of January 2016, the department is allowing only MASH-compliant safety hardware to be included on the QPL. As the implementation dates provided by the FHWA are reached, existing NCHRP 350-compliant safety hardware on the QPL will be removed.”

Project NH-15 (180) called for narrow-low maintenance crash cushion systems, as well as a wide-low maintenance system for permanent installations. Although MASH units were not specifically called out for this project, TDOT’s QPLs included several MASH units that would be acceptable. Site-Safe LLC of Leitchfield, Ky., the crash cushion installer, quoted Trinity Highway’s QuadGuard M10, which consists of an engineered steel nose and crushable, energy-absorbing cartridges surrounded by a framework of steel quad-beam panels. The system is MASH Test Level 2 and Test Level 3 compliant as a re-directive, non-gating crash cushion. TDOT agreed to the use of the system. Once assembled in its yard, the units were easily transported and dropped into place and anchored, minimizing installation time on the roadside. Installment of the MASH systems was in accordance with TDOT specifications and additional MASH roadside systems will be added to Tennessee’s roadways in the future.

“It’s comforting to know that we have agencies such as TDOT procuring roadside safety hardware that meet the latest standards in the industry” said Site-Safe President David Rich.

Source: Roads & Bridges magazine