There has to be a better way of keeping road crews safe than putting one of them in harm’s way.
Truck-mounted attenuators (TMAs) attach to the back of a work truck to absorb the impact when a distracted driver, despite all other indications that construction lies ahead, plows his car or truck full-speed into the work zone. The TMA truck’s job is to follow a vehicle that’s placing material and/or equipment and cushion the blow. The first truck is the leader truck; the second, the shadow truck.
The National Work Zone Safety Information Clearinghouse categorizes the attachments as portable positive protection devices. They’re an easily installed but effective way to protect crew members from being hit from behind (longitudinal protection) and from the side (lateral protection) by vehicles in lanes next to the work zone. They minimize congestion because you can quickly move them in and out of place, and are less expensive than putting up a concrete barrier.
The 2009 edition of FHWA’s Manual on Uniform Traffic Control Devices (MUTCD) mostly states that attenuators are optional (using “Ctrl F” and searching for “attenuator” finds 32 mentions). It’s up to each state to then mandate it.
The attachments cost about $13,000 to $22,000 depending on the vehicle – flatbed, dump, etc. – you’re buying it for. Attenuator trucks are about four times that; I found a 2017 Isuzu NPR XD attenuator listed for $60,000.
They seem to be worth the investment.
A 2014 article in Transportation Research Record: Journal of the Transportation Research Board confirms the attachment cuts road worker and car and truck driver injuries and fatalities from rear-end crashes almost in half. “Agencies can recoup the cost in less than a year of daytime work shifts on facilities serving at least 20,000 vehicles per day and of nighttime work shifts on facilities serving at least 50,000 vehicles per day. (To buy “Analysis of Expected Crash Reduction Benefits and Costs of Truck-Mounted Attenuator Use in Work Zones,” ISSN: 0361-1981, DOI 10.3141/2458-09 for $25, click here.)
There’s one fly in the ointment, however: The driver of the vehicle equipped with the device is a potential sacrifice to the gods of roadbuilding.
Technology is close to eliminating those injuries and deaths.
Military technology put to civilian use
The Florida DOT is aggressively researching and testing both autonomous vehicles and connected vehicles (cars that “talk” to each other and roadway infrastructure to help drivers avoid crashes) to gather data that proves the technology is safe and reduces congestion. The agency has worked with state legislators and the U.S. DOT to make Florida the first state to allow autonomous vehicles on public roads and attract technology companies interested in using the agency’s connected vehicle affiliated testbed along I-4.
One pilot project is testing how well Mobileye’s Advanced Driver Assistant System (ADAS) audiovisually alerts drivers: to errant vehicles, bicycles, and pedestrians. Fifty public transit and agency vehicles have ADAS and Geotab Inc.’s GPS device; another 50, the benchmark group, have only the GPS device.
The agency’s third annual Automated Vehicles Summit in 2015 featured technology developed to easily convert military vehicles from manned to unmanned operation. Micro Systems Inc. of Fort Walton Beach, Fla., installed its vehicle automation kit in an H2 Hummer.
Consisting of a steering actuator (essentially, a motor) that installs without removing the steering wheel, actuators for acceleration and braking, transmission controller, an active safety system, and a roof-mounted navigation module (NavModule) with GPS receiver, digital compass, radio transceiver, and system control computer, the Multi-Platform Appliqué Kit (M-PAK) supports leader/follower teaming – the configuration transportation departments use in work zones.
When you install a NavModule on both vehicles, the “shadow” vehicle follows the leader vehicle’s exact same path at the exact same speed without a driver.
That’s what a large work truck manufacturer did to create an autonomous TMA (ATMA) truck. Royal Trucking & Equipment Inc. of Coopersburg, Pa., demonstrated the technology for the Florida DOT using a maintenance truck.
“We’ve been playing with the concept of an unmanned TMA for a long time,” CEO Robert Roy told ABC News in July 2016. “Over the years, we’ve applied as much technology as we can, converting trucks from ‘dumb’ to smart. They’re the last line of defense to save lives in work zones. As infrastructure decays and more road construction is needed, a lot of states are starting to recognize the value of these trucks.”
Micro Systems’ M-PAK can be installed on any vehicle type. Potential public works maintenance applications include blacktopping, line painting, sign removal, and traffic signal repairs anywhere a barricade can’t be erected.
A year-long pilot project using two Florida DOT work trucks is on hold, but Royal Trucks is talking to four other state DOTs to test the technology. If you’re interested, contact Marketing & Business Development Manager Samantha Schwartz at [email protected].