Merriam-Webster defines a platoon as “… two or more squads usually led by one lieutenant.” Change “squads” to “trucks” and “lieutenant” to “driver” and you’ve got the definition of what is currently taking the trucking world by storm.
Platooning isn’t a new concept, but recent advances have made it a viable, cost-savings transportation option for trucking fleets in the not-so-distant future.
In a platoon, two or more trucks connect electronically to become a semi-autonomous moving train, where the lead truck controls the trailing vehicles through a wireless communications system that is also connected to the Internet. The first truck tells the trucks behind it what actions the lead driver has taken, such as braking or accelerating, and the rear trucks immediately follow suit without driver intervention.
Platooning allows the connected trucks to travel very close in line, reducing aerodynamic drag for all the trucks. The result is improved fuel economy without compromised road safety. The trucks are in constant vehicle-to-vehicle (V2V) communication sharing action and data. If the lead truck’s collision mitigation system activates its brakes, the rear trucks slow down, too.
According to Josh Switkes, Founder and CEO of Peloton Technology, which has chalked up thousands of highway miles in platooning testing, “… the rear truck knows exactly what the front truck is doing… (There are) about ten milliseconds between when the front truck's brakes are applied and when the rear truck knows about it.”
The trucks in the Peloton platoons are ordered by their braking ability, with the truck that can stop the shortest and quickest positioned in the rear. Network Operation Center, the cloud-based technology the trucks are connected to, helps determine positioning and the following distance between each truck. Peloton only platoons when conditions—road, weather and traffic—are optimal.
Because of the close positioning, the rear driver’s forward vision is impaired. That’s where a video feed taken from a camera at the front of the lead truck comes into play. “We send that video feed to the rear truck through the wireless communication, so the rear driver sees the road ahead,” explained Switkes. “You use it like another mirror.”
Peloton’s truck platooning system builds on advanced safety technologies such as collision mitigation systems like those developed by PRECO Electronics, and adaptive cruise control systems. Trucks are electronically connected through a combination of V2V communications, radar-based active braking systems, and proprietary vehicle control algorithms.
With the Peloton platooning technology, each driver maintains steering control. According to Switkes, “The second (and third) driver has complete control. He or she is engaged all the time. We're not replacing the driver. We’re taking their skills and adding an extremely fast braking reaction.”
However, the newest wave of truck platooning has just hit the European highways, and this time autonomous steering is at the wheel. Daimler Trucks recently did a live public platooning demonstration on the autobahn in Germany of its latest Highway Pilot Connect technology. Two trucks followed a platoon lead, and switched control to autonomous accelerating, braking and steering.
"We all know, platoons are not completely new.... but what we do today is not just more of the same ... it's not just another platoon," explained Sven Ennerst, head of Daimler Trucks' global development. "Our platoon today is something the world has never seen before... the reason is the trucks in our platoon are semi-autonomous [with the new Highway Pilot Connect]."
With this latest technology, trucks are equipped with both linear and lateral guidance systems. As a platoon, the trucks are electronically connected and programmed for a specific route, but they can each be operated independently as an autonomous driving truck. For instance, drivers can activate autonomous steering during long, monotonous stretches.
The V2V communication between the trucks makes room for other vehicles to change lanes into the middle of the platoon. The truck behind the vehicle that has just entered the lane automatically slows to lengthen the following distance from 15 meters (just under 40 feet) to the legally required 50 meters between cars, and then readjusts to 15 meters after the car has left the lane. This adjustment is done independent of the drivers.
The short distance between platooning trucks is what helps fuel economy. Platooning creates airflow between the connected trucks that helps push each truck forward. Peloton has tested platooning at 65 mph and found that connected trucks gain more than 7% fuel efficiency—nearly 5 percent for the lead truck and 10 percent for the trailing trucks.
Activating platooning is as simple as pushing a button. A blue button switches on the automated driving mode in the Daimler Highway Pilot. A signal transmits to other trucks that Highway Pilot Connect is available, and the driver of another platoon-capable truck can join the platoon simply by pushing their own blue button. Their trucks link and automatically the new truck positions itself 15 meters behind the lead truck.
The rear driver sees the traffic conditions and driving route on his or her in-cab screen from data transmitted from the lead truck. More trucks can join the platoon—as many as 10 trucks can safely connect, according to Daimler.
So the question is, who will use platooning once it is universally approved? According to a recent study by the American Transportation Research Institute (ATRI), Peloton and others, trucks in large U.S. fleets most readily platoon with other trucks from the same or other large fleets. “We charge fleets a per-mile fee while their trucks are platooning and saving fuel,” says Peloton’s Switkes.
Owner-operators, however, are more apt to platoon with other owner-operators. Crossover between large fleets and small owner-operators might be more of a challenge. While the cost-savings in fuel efficiency is real, the study found that both large fleets and owner-operators might be reluctant—at least at first—to pay the other for platooning.
Positioning matters, too. “If the rear truck has better fuel economy, and the trucks are from different fleets, how do you share the fuel economy in a fair way?” asks Randy Mullet, Vice President for Government Relations and Public Affairs at Con-Way.
The ATRI study found that truck platooning is “near market-ready for industrial use and will provide value in specific roadway and operating conditions for heavy truck fleet operations.”
While costs vary, most fleets outfitted with platooning technology see a return on investment in seven months or so.
Mullett says that for U.S. market-readiness, technology is not the issue. “It’s the policy issues that need to be worked out. For instance, we need harmony on following distance, because there are minimum following distances in some states. Also, how do we keep cars from jumping in and out of the space between trucks? There also needs to be commonality about things like where to place the video screens so you don't confuse drivers using different vehicles.”
While European countries are opening their freeways to platooning, it might take the U.S. a few more years to reach common ground between state laws and nationwide policies to make platooning a common occurrence on our roadways. When it does become a common sight, these truck trains will be a sight to see, indeed.