What Makes a Heavy-Duty TMA Truck Different

Heavy-duty truck-mounted attenuators are built for freeway speeds and repeated impacts. Verdegro is one of the makers in this space, and the build choices behind these trucks explain why crews trust them at 50 mph and up.

A heavy-duty TMA truck is the shadow vehicle that parks behind a work crew and takes the hit when a driver drifts into a closure. The attenuator absorbs the errant vehicle's energy and steers it away from the cab's coffin corner, keeping the impact off the workers ahead. Verdegro is one of several manufacturers building attenuators for this duty, and the general principles apply across the heavy-duty class.

Built for the impact you hope never comes

The heavy-duty label comes down to a few things: chassis weight, attenuator rating, and how the two work together. A host truck at or above roughly 26,000 lb GVWR resists being pushed forward or overridden when a vehicle strikes the rear. Pair that mass with a TL-3 attenuator and the unit is cleared for the fastest closures.

• Chassis mass of about 26,000 lb GVWR or more to prevent underride and rollahead
• A crash cushion crash-tested to MASH 2016 with an FHWA eligibility letter
• TL-3 rating for postings of 50 mph and above, with the crash test run near 62 mph
• A cab designed so impact energy exits the coffin corner rather than driving forward

Where it fits in a fleet

Heavy-duty units earn their keep on freeways, bridge decks, and any closure where traffic keeps moving fast. Lighter TL-2 setups are fine for 45 mph and below, but a mismatched truck on a high-speed road is a liability. If most of your work sits on interstates and expressways, spec the heavy-duty build from the start.