Frequently Asked Questions

TMA Truck Basics

TMA Operation

Cushion & Crashes

Company & Products

TMA Truck Basics

What is a TMA Truck?

A TMA, or truck mounted attenuator truck, is placed strategically in a highway work zone to protect workers from errant vehicles in oncoming traffic. This truck has an impact attenuator, or crash cushion, that absorbs the kinetic energy of the colliding vehicle.

What are other names for a TMA Truck?

Operation of the ATMA includes a Leader/Follower configuration. A human-driven leader vehicle is followed by an driverless follower vehicle (the ATMA). The leader vehicle is outfitted with a NAV Module. This module contains a GPS receiver, system computer, digital compass, and a transceiver. It transmits GPS position data called "eCrumbs" back to the follower vehicle, which then uses the data to follow the exact path and speed of the Leader vehicle at each point along the route. The NAV Module can be easily unstrapped and removed from one vehicle and installed on another if a different leader vehicle is required. Click here to learn more!

Are TMA trucks only used for roadway operations?

No. While TMA trucks can be used to protect your workers in many different types of operations, one area we’ve seen TMA trucks increasingly used in is traffic incident management. Emergency responders, including law enforcement, fire/EMS personnel, and tow truck operators, are often left dangerously working in direct exposure to passing traffic. With a TMA present, these workers can effectively and safely work on the operation at hand.

How dangerous are work zones?

Extremely! In 2020, there were over 800 fatalities in work zones across the country. Just last year, 67% of highway contractors in the United States reported crashes in their construction work zones. In fact work zone crashes have become so common that it’s no longer if a crash occurs but rather when it will occur. Given these concerning statistics, not having a TMA truck in your work zone leaves your work crews exposed to errant drivers and puts them at risk of significant injury or even death. For the latest statistics, visit the National Work Zone Safety Information Clearinghouse.

Why should I have a TMA truck in my fleet?

The most important reason is to keep your work zone and workers safe. Each year in the US, a work zone crash occurs approximately every 5 minutes. It has become almost inevitable that a highway worker will experience at least one, if not more, crashes in their career.

Does the weight of a TMA truck matter?

Yes. If you plan to utilize the truck on roads with speed limit of greater than 60mph, your TMA truck should have a minimum operating weight of 20,000lbs +/- 1,000lbs. An attenuator truck that does not meet this recommended weight is susceptible to an increased roll ahead distance. In the event of a crash, this puts working crew members in potential danger, increasing the likelihood of injuries or fatalities.

Why choose air brakes over hydraulic brakes?

A TMA truck with air brakes, in a staionary work zone, with the parking brakes applied, has both rear brakes (which are substantially larger) engaged by springs. In a TMA truck with hydraulic brakes, the parking brake is applied with a hand lever attached by a cable. In the event of an impact with significant G Force the parking brake could fail, allowing the vehicle to free wheel into the active work zone, endargering the lives and safety of the men and women working in front of it.

TMA Operation

Do I need a CDL to drive a TMA truck?

The majority of our trucks are weighted to less than 26,000lbs so you don't need a CDL to drive them however different states have varying regulations. Visit our Help Center to request a regulation guide for your area of operation.

Do I need any special training to drive a TMA truck?

In the United States, there is no formal training required to be a TMA truck driver. However if you are considering driving a TMA truck, we recommend looking into training offered by ATSSA (American Traffic Safety Services Association), specifically the course for "Operation and Application of Truck-Mounted Attenuators (TMAs)".

Can I raise or lower the attenuator while driving?

No. You should never raise or lower the attenuator while the truck is in motion. Always come to a complete stop, park the vehicle, and ensure the area around your TMA truck is clear before deploying or stowing the attenuator.

Does a TMA truck require frequent maintenance?

Routine maintenance is required to ensure that your TMA truck is operating properly and continuously providing the needed level of safety to protect workers in the work zone. For more information about how to properly maintain your TMA, watch our Maintenance Series videos. If you own a Royal truck and have questions about maintenance, contact our Service and Parts Team.

Cushion & Crashes

What should I do if my TMA truck was hit?

If your TMA truck has been hit, you should not attempt to repair it yourself. Instead, take it to a Certified Attenuator Repair Facility where it will undergo the necessary post-impact procedure. This procedure is used to determine the extent of the damage and whether the attenuator can be repaired or needs to be replaced. Once this inspection procedure is completed, only then can the TMA truck safely return to the work zone. It is critical that you have the procedure performed by a certified facility as structure damage may sometimes be internal and not visibly obvious. Learn more about the process by watching our Crash Protocol video.

What is roll ahead distance?

Roll ahead distance, or RAD, is the distance a TMA will be displaced in the event of an impact. This is extremely important to know so your attenuator truck does not roll into your work zone. Many states require a specific distance between the truck and workers. Learn more here.

Does the TMA truck's attenuator depreciate after an accident?

No. Attenuators (both truck mounted and trailer mounted) are considered sacrificial “life saving devices that are purposely placed in harm’s way.” As such, its value is measured by its ability to perform. The only time its value can ever be depreciated is if it can no longer attenuate the energy from a crash into it to the same degree it did when it was new. At that point, it must be removed from service and repaired/replaced.

What does MASH-Approved mean?

An attenuator's crashworthiness is determined through tests outlined in the Manual for Assessing Safety Hardware (MASH). A MASH-approved TMA is an attenuator that has passed all of the tests outlined in this manual. As these critical safety tests are made to replicate real world crash scenarios, we highly recommend only having MASH-approved attenuators on the trucks in your fleet.

What is the difference between MASH and NCHRP 350?

The NCHRP Report 350 was the original set of testing parameters and uniform guidelines that represented recommended procedures for the performance evaluation of permanent and temporary highway safety features. MASH was first published in 2009 and was updated in 2016 – it became the replacement for the NCHRP 350. MASH expands upon the testing requirements listed in the NCHRP 350 Report and primarily focuses on test vehicles, impact condition criteria and evaluation criteria. Key to the new guidelines is that they also address the question of when MASH-tested and approved attenuators must be used on TMA trucks.

Company & Products

What makes Royal TMA trucks different?

Many TMA trucks might look the same, but they’re not all built the same. Every truck we build has been designed and engineered to address the specific safety needs and concerns of our customers, so you can give your crews the highest level of protection possible. From the biggest features, such as the connected arrow board, to the smallest details, like the protected wiring, everything that goes into the build of the truck is carefully designed to ensure your workers are safe and your operations run smoothly.

What is an ATMA?

The ATMA (Autonomous TMA) truck is a self-driving TMA truck that operates completely driverless in a Follower mode when paired with a Leader vehicle. This eliminates the need for a worker to drive a vehicle that is intended to be hit. The innovative technology was first developed for use by the U.S. military and has since been adapted for the roadway construction industry through our partnership with Kratos Defense. Read more about our Autonomous TMA Truck.

I need to rent a TMA truck in the future. How far in advance should I contact Royal?

As soon as possible, especially if you need to rent more than one truck. TMA trucks are becoming necessary in many more roadway construction operations across the U.S. so finding available trucks is increasingly difficult, especially during peak season. By contacting us as soon as possible, you are more likely to secure your rentals. Through our national Royal Rental Network, we will always work with you to connect you with the trucks you need whenever and wherever you need them! To learn more about our Rental Network or to request a rental, visit our TMA truck rentals page.

My company performs different operations. How can I get the most out of my fleet?

Underutilized fleets are a harsh reality for many organizations. Needing specialized vehicles for different operations leads to long periods of inactivity when they are not in use. To help our customers maximize their fleet utilization, we've developed the 3-in-1 (stake body truck, TMA truck, cone safety truck) and the Hook 'N Go truck. Both multi-purpose trucks can be altered in minutes for your varying operations. Learn more about our multi-purpose trucks for your fleet.

Is there a safe way to prepare my workers or test new hires?

A comprehensive training program is a critical step in ensuring your workers are performing their jobs safely. Traditional training programs such as video, text, and classroom instruction are effective methods for teaching work zone safety however they fall short in experiencing work zone safety. Virtual Reality training (or VR, for short) has been developed to bridge this gap and better prepare workers for the reality of work zone dangers. VR allows them to experience what it feels like to be in a work zone, firsthand, but from the safety of an office. Learn more about VR training for safer work zones here.