Out of a light rain, three rigs in close formation hit the first banked curve at the Transport Canada test track in Blainville, Que., on Oct. 21. They barely disturb the air as they slip by, one, two, three, separated by a radar-measured, computer-controlled 59 feet, traveling 55 mph.
We’re witnessing the tail end of fuel consumption trials of what many people have been working to make part of the future of long-distance trucking: groups of two, three, maybe four trucks connected by systems that synchronize and control their spacing, speed, braking and maybe even steering – all depending.
The short term for this driving in tight formation is called platooning. It capitalizes on the reduced aerodynamic drag that comes with traveling in close formation – like Olympic cyclists and Indy 500 cars – thus, saving fuel. Even as the October trials were winding up, the National Research Council Canada (NRC) was able to report that the three test trucks achieved a combined fuel savings of about 6% for rigs with no aerodynamic devices attached, and 7% when equipped with trailer tails and side skirts.
When a truck closes in on another truck, it enters the wake of the truck ahead of it. Because the air in the wake is moving slower, it causes less drag for the following truck, thus reducing fuel burn. As well, the following truck is pushing air ahead of it, which, at a close enough distance, pushes on the lead truck, reducing its fuel burn too.
This is the idea. But there are aerodynamics-related questions that need answering. Is there an optimal inter-truck distance for reducing drag? Which of the trucks in a platoon gets the greatest fuel savings? Do trailers fitted with aerodynamic devices like trailer tails and side skirts get higher fuel savings than those that are not?
The October trials were designed to shed light on these questions.
The credit roll for the 20-day Blainville test program is long: The specially outfitted Volvo tractors came all the way from Berkeley, courtesy of the California PATH Program (Partners for Advanced Transportation Technology). Created in 1986, PATH researchers have logged more than 600 person years of work to date studying driving automation systems.
Transport Canada was the project lead, handling tasks such as track access at its Motor Vehicle Test and Research Centre (MVTC) in Blainville, logistics, shipping, temporary importation of the tractors and funding. NRC was in charge of the experimental design and data analysis. FPInnovations’ PIT Group lent its expertise in running the track trials, providing equipment, personnel, track logistics and more.
One of Quebec’s government-run truck training schools, the Centre de formation du transport routier de Sainte-Jerome (CFTR), lent instructor-drivers. Other key parties included PMG Technologies, which manages the MVTC, Volvo Trucks, and the US Federal Highway Administration.
The three Volvos were equipped with what is called a vehicle-to-vehicle (V2V)-based cooperative truck platooning system (CTPS), which PATH developed. It includes radar, video cameras, radio communications between the Volvos, on-board computers and cab displays for the drivers and researchers. For the Blainville trials, once the drivers brought their rigs up to test speed, they turned their rigs over to the CTPS, which controlled the speed of the trucks and spacing.
Transport Canada’s interest comes from its ecoTechnology for Vehicles program, which studies advanced transportation technologies. In this case, Transport Canada wanted to investigate five aspects of platooning, says Ryan Klomp, director of environmental and transportation programs, Transport Canada.
“Fuel economy, aerodynamics, system reliability; for example, is it engaging as anticipated?, driver feedback, and commercial readiness. This is the first time CTPS has been tested in Canada,” he says.
Of particular interest in these trials were fuel consumption and emissions performance under various operating conditions and vehicle configurations. To that end, over many sets of runs, data were collected on several variables. For example, the platoon was run at four time gaps, 0.6, 0.9, 1.2, and 1.5 seconds, representing spacing of 60-140 ft. Two speeds were tested: 55 mph and 65 mph. The trailers were run with (“aero”) and without (“standard”) trailer tails and side skirts. They were also run empty and with 35,000-lb loads.
The teaser results presented Oct. 21 included an interesting breakdown of fuel savings, at 65 mph and loaded: The lead truck got nothing more out of the experience than the best view, regardless of the time gap or whether it was equipped as aero or standard. The middle truck won a 7% fuel savings in standard, and 9% in aero trim, decreasing to 7% and 6%, respectively, as the gap increased to 1.5 seconds. The trailing truck won a 13% fuel burn reduction in aero and 11% in standard, decreasing to 11% and 9%, respectively, at a 1.5 second time gap.
Transport Canada will be making the full results public. “We will present some preliminary results at the Task Force on Weights and Dimensions in December in Montreal,” Klomp says. He expects that the full technical report will be made available in late winter 2016 or early spring 2017.
News of the driver feedback and buy-in will be important. But Martin Combe, a teacher at CFTR and part-time driver, who drove the middle truck, one of two positions I rode in, found the 59-ft gap easy on the nerves and told me that the ride was extra smooth with the trailer tail and side skirt attached.
Transport Canada couldn’t say when road trials might begin, let alone when platooning might become an everyday sight on Canadian roads. But while it collects test data and ponders other considerations, such as regulatory and enforcement issues, cut-ins by other vehicles, passing lanes, specific highways, drivers and driving conditions, it is keeping the provinces and industry stakeholders in the loop, Klomp says.
“We do have a federal/provincial committee under the program comprised of heavy vehicle regulators,” he says.
There are also tough questions of economic viability that must be addressed. PATH suspects that CTPS is too complicated to sell as an aftermarket product – that CTPS-capable tractors will likely have to be purpose-manufactured.
Platooning will also have to prove its worth against existing two-and three-trailer configurations, such as the well-established long combination vehicle (LCV), which costs about 35% less per run to operate than two tractor-trailers.
One fleet engineer I spoke with poo-pooed the value of running three-rig platoons compared to LCVs, but did muse about the possibilities of platooning two LCVs.
There is a lot more to be said about what role platooning might play in Canada. Stay tuned.
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