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Attenuators (TMA, TTMA, and TA)

A truck mounted attenuator (TMA) or trailer attenuator (TTMA or TA) is impact attenuator permanently mounted on a truck or temporarily attached with a hitch. They can also be known as a crash cushion, crash attenuator, or cowboy cushion. 


What is a TMA?

A TMA is a device intended to save lives and reduce the damage to structures and vehicles after an errant motor vehicle collision. “Their design enables them to absorb the colliding vehicle's kinetic energy. Crash cushions are constructed of multiple segments, which crumple into each other when collided with to absorb the impact. Their main benefit is in their reusability; these attenuators can automatically return to their original position after a crash.” [1]


Why do I need a TMA?

If you want to save the lives of motorists and your construction and maintenance crews, you need a crash attenuator.  They are permanently or temporarily affixed to a shadow vehicle and strategically placed in the lane closure.


Most DOTs require construction and maintenance crews to use a TMA or TTMA while building or repair our highways and roads. It is important to check with your state DOT to understand the requirements. Not all DOT specifications are the same. You could face hefty fines, or worse, massive liability costs if there were to be an injury or death in your work zone. 


For example, here is the  TxDOT Special Specification 6185 for Truck Mounted Attenuator (TMA) and Trailer Attenuator (TA). Some of the specifications are as follows. Level 2 compliant TMAs are approved for use only on roadways with regulatory speed limits of 45 mph or less. Level 3 compliant TMAs may be used on any TxDOT facility. The host vehicle for the TMA and TA must weigh a minimum of 19,000 pounds. A must have resource is the TxDOT Compliant Work Zone Traffic Control Devices publication, dated 2017. Here is a great article about how Texas has improved its TMA requirements in 2017 and made our roads safer.


How do I get a attenuator?

GSI carries TMAs and TTMAs that meet all TxDOT and most county and municipality specifications. They are in stock and ready to ship today. GSI also carries replacement parts for repair of your impacted crash attenuator.

Call (972) 2251660,, or come by our yard at 720 West Wintergreen, Hutchins, Texas 75141. We do ship.

TMA - Truck Mounted Attenuators
TTMA or TA - Truck Mounted Attenuators
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