By: Powered by Gregory Highway
A trailer truck mounted attenuator (TTMA) is a roadway safety device designed to protect work zones in the event of a work zone intrusion. Hitched to the back of a truck, the TTMA is designed to absorb the impact of a vehicle collision, minimize damage to work zone assets (equipment and/or personnel), and reduce the forces on occupants of the impacting vehicle. All of these events ultimately lead to saving lives on our roadways.
The TTMA-200 from Gregory Highway is an AASHTO MASH 2016 Test Level 3 (TL-3) crash cushion designed for use with a support truck in both stationary and moving work zones. The galvanized steel attenuator connects via a standard 8-ton pintle hitch mount, eliminating the need for a dedicated support vehicle. It can be used with most supporting vehicles weighing 10,000 lbs. or more and can be switched between different vehicles in minutes.
Its flexible configuration makes it easily adaptable to sweeping, salting, mowing and striping operations and can be equipped with optional items, including arrow board stand, arrow board and hitch extensions.
“If a crew is out on the highway doing safe mowing or trash pickup, or anything pertaining to the roads, they’ll often have a TTMA trailing behind them as they’re moving down the road. Arrow boards attached to the attenuator make traffic aware that there are people in front and that the traffic needs to go around them,” says Nicole Headlee, a manager with Highway Safety Specialists (HSS), which assembles TTMA-200s for Gregory Highway.
In the event of a vehicle collision with the attenuator, an oversized mandrel pushes into a smaller tube, splitting it into four strips of metal to dissipate the impact energy. This banana peel effect means the metal strips remain with the trailer and pose no hazard to adjacent traffic. This allows the trailer frame to serve as the energy absorber, which simplifies the design, reduces cost and minimizes the impact on the driver of the vehicle that causes the impact.