What is the Difference Between NCHRP-350 and MASH-2016 Standards?
If you manage highway construction, traffic control, or public infrastructure projects, you are likely familiar with the terms NCHRP-350 and MASH-2016. Both are crash-testing standards that dictate the safety requirements for roadside hardware, including temporary work zone devices, sign stands, and barriers.
However, as vehicle sizes and weights have evolved over the decades, so too have the standards required to keep roadways and work zones safe.
Here is a breakdown of the differences between the two standards, why the industry shifted to MASH, and what it means for your current traffic control inventory.
The Short Answer
The primary difference is that MASH-2016 is the modern safety standard that utilizes heavier test vehicles and sharper impact angles to reflect the larger, heavier vehicles (like modern pickup trucks and SUVs) on today’s roads. It replaces the older NCHRP-350 standard, which was based on the lighter, smaller vehicle fleet of the early 1990s.
What was NCHRP-350?
Published in 1993, NCHRP Report 350 (National Cooperative Highway Research Program) served as the foundation for crash-testing standards for over two decades. It defined how roadside hardware—ranging from permanent guardrails to temporary sign stands and channelizing devices—was tested for vehicle impact performance.
For many years, achieving an NCHRP-350 compliance letter from the Federal Highway Administration (FHWA) was the gold standard for deploying equipment on federally funded roadways.
What is MASH-2016?
MASH stands for the Manual for Assessing Safety Hardware. Published and periodically updated by the American Association of State Highway and Transportation Officials (AASHTO), MASH was created to address a glaring reality: the vehicles on the road in the 2010s were significantly larger and heavier than those in 1993.
The 2016 edition of MASH represents the current benchmark. It introduces stricter, more realistic crash testing criteria designed to ensure that roadside safety hardware performs effectively when struck by modern vehicle profiles.
Key Testing Differences
To pass MASH-2016 testing, highway hardware must withstand significantly more punishing impacts than what was required under NCHRP-350.
| Testing Metric | NCHRP-350 | MASH-2016 |
|---|---|---|
| Pickup Truck Weight | 4,400 lbs | 5,000 lbs |
| Small Car Weight | 1,800 lbs | 2,420 lbs |
| Small Car Impact Angle | 20 degrees | 25 degrees |
| Terminal Impact Angle | 20 degrees | 25 degrees |
| Windshield Damage Criteria | Subjective / Qualitative | Objective / Quantitative |
Are My NCHRP-350 Devices Still Legal to Use?
A common misconception is that the introduction of MASH instantly rendered all NCHRP-350 equipment illegal or obsolete. This is not the case.
According to the AASHTO/FHWA Joint Implementation Agreement:
- The Grandfather Clause: Temporary work zone devices manufactured on or before December 31, 2019, that successfully passed NCHRP-350 testing may continue to be used throughout their normal service life.
- New Equipment: Any temporary work zone devices manufactured after December 31, 2019, must be successfully tested to MASH-2016 standards.
- Modifications: Any changes or modifications made to existing NCHRP-350 eligible hardware automatically trigger a requirement for re-evaluation under MASH guidelines.
Note: While federal guidelines permit the continued use of older equipment, individual State Departments of Transportation (DOTs) may enforce stricter local sunset dates. Always verify your specific state DOT specifications before deploying equipment.
Eastern Metal’s Commitment to Compliance
At Eastern Metal Signs and Safety, we prioritize the safety of roadway workers and drivers above all else. As the industry transitions fully to modern safety standards, we have engineered our product lines to meet the rigorous demands of MASH-2016.
Whether you are looking for our heavy-duty, MASH-compliant APEX Series sign stands designed for maximum wind deflection, or need guidance on transitioning your aging inventory, our team is here to help. We proudly supply a comprehensive line of MUTCD, NCHRP-350, and MASH-compliant equipment designed to meet the specific requirements of your job site.
