While the hybridisation and eventual full electrification of truck tractor units and rigid vehicles of various sizes is inevitable, with primary manufacturers launching plug-in or solely electric trucks this year onwards, another landmark advancement is simultaneously being worked on – platooning. But is the arrival of road transport platoons a foregone conclusion or might various factors eventually see it taken off the agenda?
From addressing what platooning is, when it started being mooted in commercial vehicle circles, and which companies have been and still are pioneering the technology, to its potential benefits, criticisms and viabilities, and the technologies that lie behind it all, we discuss whether truck platooning is likely to become a road transport reality.
The ACEA 2017 whitepaper entitled ‘What is truck platooning?’1 sums it up fairly well, explaining that it is “the linking of two or more trucks in convoy” where they “automatically maintain a set, close distance between each other when they are connected for certain parts of a journey, for instance on motorways.” However, its definition explicitly states that platooning uses “connectivity technology and automated driving support systems”, which isn’t always the case, as we shall go on to explore.
Paraphrasing the remainder of the ACEA’s fundamental definition, the truck at the front of the platoon acts as the leader, while the drivers of the vehicles following behind it, which will be of very similar form and size, maintain the same speed and copy the lead unit’s lane changes and other driving behaviours. Autonomous versions of follower vehicles are sometimes referred to as ‘drones’ – not to be mistaken for the ones that fly and are typically used for aerial filming, or indeed for human-driven trucks.
The ultimate vision of platoon developers is still perceived as involving fully autonomous trucks and trailers that are able to operate non-stop, but as this article addresses, numerous voices from road transport operators and safety bodies to technologists, manufacturers and, of course, drivers, are forming not quite as radical, much more hybrid ideals.
For now, three main variations of platooning continue to be referred to - scheduled, orchestrated and ‘on-the-fly’, the first two being self-explanatory and the third referring to the informal, ad-hoc formation of platoons when trucks and trailers or rigids happen to be in the same place and heading to the same destination.
Additionally, platoon projects are typically classed as single or multi-brand, referring to whether a convoy comprises different truck and trailer manufacturers’ products.
Reduced congestion and increased road capacity: Nobuo Iwai, senior researcher on one of Japan’s key platoon projects, in Tsukuba City in this case, commented in a BBC Future article that truck platooning technology is partly being pioneered to “lead to a reduction in the amount of road space used by vehicles, which would help to reduce traffic congestion”. With platooning tipped by some commentators as potentially doubling the capacity of certain motorways, it would certainly be remarkable to behold on UK motorways and perhaps on ‘smart’ stretches in particular, which do seem to be having a palpably positive effect in congestion and traffic flow terms as it is – except when accidents, breakdowns and other hiccups occur.
Maximising road transport operators’ offerings and satiating ever more demanding customer expectations: If fully autonomous truck platoons do eventually appear on the world’s roads, likely starting with developed countries, it would mean the negating of the current crop of sensible human frameworks in force such as the Working Time Directive, drivers’ hours tachograph and rest regulations, and duty limits, which are all nicely summarised by the HGV Alliance6. Convoys of perhaps a dozen tractors and trailers, potentially fully or partially comprising longer semi-trailers (LSTs), will be able to drive continuously day and night on suitable roads, delivering an ever-growing amount of goods to end customers, confined only by fuel ranges, which will likely by that stage be partly or completely electrified.
Lowering serious injuries and road fatalities caused by driver fatigue: Putting to one side for a moment the potential driver job-losses that would almost certainly ensue following the introduction of fully autonomous platoons, they have the potential to reduce sleep-related RTAs, 40% of which ROSPA’s July 2020 factsheet7 states involve commercial drivers. The prominent road safety organisation explains that “HGV drivers report increased levels of sleepiness and are involved in a disproportionately high number of fatigue-related accidents” and comments that “crashes caused by tired drivers are most likely to happen […] on long journeys on monotonous roads, such as motorways [...] between 2am and 6am.” If hauliers can eventually operate fleets of driverless or indeed part-human platoons, it could help to make smart motorways like the M6 nearby Tiger Trailers’ Cheshire factory safer, where driver error still currently contributes to a large proportion of accidents, many of which involve HGVs.
Fleet cost savings: The 'Intelligent truck platooning: how to make it work' document8 by the Technical University of Denmark, released more than two years ago, actually elevates fleet cost-savings as the main aim of platooning, with fuel consumption, CO2 emissions and a reduction in idle time 'due to relaxation of resting hour restrictions' in its sights. Commercial vehicle and indeed general engineers’ interest may be piqued by learning that the close following or spacing distances between trucks-trailers could lead to air drag friction reduction as promising as 24% at 1m gaps28, while the SMMT9 revealed that “figures produced by the ACEA projected that platooning could reduce the CO2 emissions of trailing vehicles by up to 16% and of lead convoy vehicles by 8%”, which is certainly not to be sniffed at by cost-conscious operators in today’s highly competitive parcel delivery, logistics and other road transport sectors. Interestingly, National Renewable Energy Laboratory (NREL)14 evaluations point to even greater fuel savings of 10% for lead vehicles and, in the case of three-strong platoon convoys, 17% fuel savings for the truck and trailer in the middle.
Following extensive targeted research online, one of the earliest truck platoon sources we identified was a January 2005 report from the Institute of Transportation Studies at the University of California, named “Development of a Heavy-Duty Diesel Modal Emissions and Fuel Consumption Model”2, the discovery of which essentially highlights that despite truck platooning and autonomous heavy commercial vehicles having been discussed sixteen or more years ago, their future remains as uncertain as that of their autonomous private car counterparts.
Congested motorways have proved a challenge for over a decade, not having merely come to the fore recently, as evidenced through unearthing sources such as the US Department of Transportation’s 2009 document “Increasing Highway Throughput”3. Richard Bishop of Bishop Consulting puts it nicely in his LinkedIn article4 “The Three Streams of Truck Platooning Development” from November 2019 which he opens by saying “To most of the world, truck platooning arose in the last few years as part of the larger automated driving wave. But there is a small and dedicated cadre of players who have pursued it for over 20 years” before revealing that Daimler/Mercedes, IVECO and Renault developed a drive-by-wire class 8 truck tractor unit as early as 1996 through the EC-funded CHAUFFEUR project, whose partners described it as an ‘electronic towbar’.
A few years later, Mercedes tested three fully automated trucks in southern Germany, enabled by infrared camera technology, but despite this seeming like a remarkably early achievement to the uninitiated, it was held back from real-world potential because the IR emitters were positioned on the rear of the trailers – which are frequently swapped between trucks.
The next meaningful advance in the field came, according to Bishop, in 2003 in California, where vehicle-to-vehicle (V2V) communication and radar achieved the small-scale platooning of fully autonomous trucks driving just 3m apart. Half a dozen years later in 2009 onwards, the SARTRE (Safe Road Trains for the Environment) project in Europe focussed on the lead truck being driven by a human, while the vehicles following could do so without driver intervention.
Similar to comparing Tesla in the autonomous and electric car realms with established car marques that have been around for decades, Bishop is likely right to assert that “incumbents don’t feel the urgency that start-ups do” as “the business of a truck OEM is in building and selling trucks, which is relatively secure as long as they keep up with their competitors, adding that “there was no ‘forcing function’ to bring out new capabilities and no evidence at the time that the highly conservative trucking market was ready for it.” His piece then goes on to describe the endeavours of Peloton, the company he perceives as the only platooning-focussed start-up on the scene, explaining that they are only close to bringing “lowly” and “uncool” SAE Level 1 automation to the market because of OEM’s relatively cumbersome product development timescales, the industry’s reluctance to embrace the idea of something so far-fetched, and because of benefit verses risk realities.
Michael Roeth, executive director of the North American Council for Freight Efficiency (NACFE), stated during a panel discussion at Michelin’s Movin’On sustainable mobility summit11 in 2018 that "lot of the technology that is required to platoon two trucks is already on the truck. Now we just have to figure out how to handle the vehicle-to-vehicle communication." He stressed that fleets shouldn’t be put off by wrongly perceiving platooning as meaning fully autonomous trucks.
Physical road characteristics: Many roads around the world will be unsuitable for platooning, especially of semi trailers pulled by HGV truck tractor units, due to their congested or physically challenging natures such as narrow sections, sharp bends or dangerous crests. Of the three main types of platooning, namely scheduled, orchestrated or ‘on-the-fly’, Jeppe Rich from the University of Denmark understandably outlines the latter as presenting a “limited match possibility” because "trucks have quite limited manoeuvre capabilities" and many corridors, or routes, simply won't be operationally viable.
Truck drivers’ perception: Peloton’s Shad Laws put it succinctly by saying “Convincing a fleet owner is easy. Convincing drivers that this is something good and that they want to use is hard”, which are comments we would agree with in the realisation that fear of technology, automation, job losses, safety and of general change and progress may create apathy or outright obstruction among some HGV drivers.
Legislation: Just like with cars from Tesla and certain German marques that feature driverless technologies, heavy commercial vehicle technology is already here in many cases, but road laws are yet to catch up and enable the legal use of such systems, politicians’ hesitation no doubt partly increasing each time the media reports a fatality involving one of Elon Musk’s cars, with the sheer relative size of HGVs in mind. The article “Is there a future for truck platooning?”12 published by the IRU, ‘the world’s largest transport organisation’, quotes Chris Spear, American Trucking Association’s CEO, as stressing “I don’t need 50 different laws, I just want one framework. And innovation will take care of the rest”, radiating the U.S’s typically enthusiastic and less-timid approach compared to the UK and EU’s, which we embrace as innovators ourselves.
Human realities: We can’t help but agree with Knight-Swift Transportation Holdings’ CEO Dave Jackson’s assertion in the Trucks.com article17 ‘Real-World Value of Truck Platooning Questioned as Support Wanes’ that "To get two drivers, two loads going to the same location at the exact same time, it just doesn’t happen very often”, which also provides the reminder that, just like with driverless cars, there will remain the risk that another vehicle could cut between platooning trucks, resulting in a collision, delays and potentially loss of life.
Return on investment: Daimler, parent company of Mercedes, which we are delighted is still very much set on introducing electric long-distance trucks, has reportedly backed away from platooning, which is a shame but understandably comes down to cost, with fuel savings having to justify the sizeable technology investment required – which critics say will never add up. We agree that managed expectations will likely see larger fleets adopt some kind of human-autonomous hybrid platooning, while for small operators it will remain financially unviable, so it’s somewhat ironic that Daimler swiftly changed its message and announced the reopening of one of its R&D centres as part of the marque’s new Freightliner Cascadia partially automated truck project, as reported by Supply Chain Dive18.
When writing in June 2020, the SMMT’s omission of a question mark from its article title ‘Truck Platooning: the future of road transport’ bestows a rather definite outlook on the whole idea – a case of when rather than if – and the body even went as far as stating that the UK’s “CV sector has seemingly waited with bated breath for this technology to become a reality on the roads”, although platooning admittedly isn’t something even mentioned by Tiger Trailers’ customers or their drivers.
Its piece documented how OEMs including MAN, Mercedes-Benz Trucks, Scania and Volvo Trucks have been enthusiastically developing on-road prototypes up until as recently as 2019, but since then the COVID-19 or Coronavirus pandemic has unsurprisingly slowed the platooning juggernaut, the SMMT explains, including a UK project led by Highways England and the DfT called HelmUK. Peloton Technology, a key player in the UK’s endeavours which had recently progressed to level two trials with automated follower vehicles, has also paused its platooning R&D, but we welcome positive vibes from HelmUK’s announcement that “all parties involved remain committed to delivering the trials which are the first in the UK to include a realistic commercial operation.”
Collaboration is almost always to be welcomed, and it’s encouraging that Volkswagen subsidiary Scania has been working alongside Toyota, a brand not as synonymous with the commercial vehicle sector, on the world’s first full-scale autonomous truck platooning in Singapore where 12% of land surface area is used for logistics. An exciting difference in this case is that the project uses public roads, the four truck-trailer combos used to transport containers between port terminals. Mobile phone company, Ericsson, was also involved with the project, providing 5G, software and mobility expertise15. We embrace Automotive World’s21 statement that “autonomous trucks are built on collaboration, not competition.”
Another company primarily associated with cars, Hyundai, has also been testing truck platooning technology but at a proving-ground in Korea rather than on public roads. It’s arguably more exciting when organisations from outside the immediate heavy commercial vehicle and road transport sphere show an interest and invest their expertise in shaking things up, and if Hyundai’s strides with the IONIQ5 car are anything to go by, their contribution to level 5 automation in the truck platooning arena, spanning V2V and V2X technology plus autonomous emergency braking (AEB) and other ADAS in scenarios simulating potential collisions, could indeed help create a ‘paradigm shift’ in the freight and logistics industry that their CV electronics head Jihan Ryu spoke of in the media16.
Tyre manufacturer, Continental, teamed up with Knorr-Bremse in 2019 to build a multi-brand platoon demonstrator fleet comprised trucks from three different OEMs. The focus was on demonstrating safe manoeuvres that will be required in the future if platooning becomes a reality, such as one vehicle in the convoy leaving, or indeed the entire platoon disengaging. Continental’s role in the project25 also included sensors and other V2V and V2X components, while Knorr-Bremse worked on commercial vehicle computational dynamics.
Exciting things will no doubt come from technology-orientated mobility pioneers including Embark, Einride and Alphabet-owned Waymo also working on truck platooning as part of their heavy commercial vehicle projects, as outlined in Interesting Engineering22.
MAN Truck & Bus19, another VW subsidiary, came out in October 2019 boldly stating that ‘platooning is the future of delivery traffic', with Dr. Chung Anh Tran from Deutsche Bahn reckoning that “at least 40% of the kilometres we cover are suitable for platooning” - a figure which may seem unreasonable here in the UK given that the DfT’s figures19 state that motorways account for just 13% of the UK road network.
The ACEA whitepaper previously mentioned documents four steps required before truck platooning could become a common sight on European roads, and although the small matter of Brexit has taken place since then, we can include the UK in such visions, even if cross-border platooning will prove even more of a challenge than at the time of the ACEA’s writing.
As with the realisation of electrified commercial and indeed private vehicles, we agree that technology, standards, road infrastructure, testing, inter-brand cooperation and legislative support will all be required when it comes to platooning, too – but, four years on, are multi-marque ‘driven’, let alone autonomous truck platoons likely to be anywhere near a reality by 2023 as the whitepaper envisaged? After all, an article on BBC Future5 dated November 2014 stated that “convoys of wireless-linked semi-autonomous vehicles could soon be hitting our roads” – something that obviously hasn’t transpired in those seven subsequent years.
A fascinating Forbes piece10 from May 2020 by Richard Bishop, who has been immersed in self-driving vehicles since 1991, reveals that “during the last year, the level of activity and funding in truck automation in general has surged while the rest of the Automated Driving Systems (ADS) industry went through somewhat of a ‘reset’”, which certainly sounds promising for road transport operators interested in and keen to adopt such technology. Bishop reiterates that fuel savings of 4% are still widely promoted for leader trucks, while followers are promised up to 10% savings through platooning, with connected braking and vehicle-to-vehicle communications a vital enabler of the whole concept which is understandably limited to motorway routes for now.
Peloton Technology’s PlatoonPro setup, which is an SAE Level 1 iteration, is release ready, requires the leader and follower to electronically ‘agree’ to be platooned, and is currently limited to just two vehicles, with the industry’s desire to double this to four vehicles “just talk”.
SAE Level 4 is where things get much more interesting, along the lines of Tesla cars’ driverless abilities, whereby the lead truck, propped up by an array of ADAS technology, is driven normally, but follower units can drive fully autonomously - although human backup is still legally mandated in case something goes awry.
Bishop’s article encouragingly identities that several U.S states including Arizona, Texas and Utah have made moves to permit automated follower platooning, with other states set to follow soon, and it’s interesting that he says “few are willing to be public about it” when it comes to the large trucking fleets supposedly interested in the technology. UPS, a customer of Tiger Trailers here in the UK, are reportedly keen, though, and have been trialling Peloton’s platooning technology over in the States.
Tunnel safety in Europe is a big deal, with crashes resulting in fatal fires having occurred in recent years, meaning that the EU’s current minimum truck following distance of 50m is legally extended to 150m in tunnels such as Mont Blanc under the Alps. Platooning is tipped to mitigate the currently problematic queues of backed-up trucks at tunnel entrances, increasing throughput as a welcome result. Understandably, though, the 1m following distance reportedly required in order to open up aerodynamic savings of 24% will cause alarm in some circles.
Sweden seems to be leading the way on the European platooning stage, with the country’s VINNOVA innovation agency having convinced Scania and Volvo to collaborate on inter-brand technology under the S4P umbrella. DB Schenker trials of SAE Level 2 platooning with two trucks have yielded good feedback from drivers who don’t seem perturbed by the concept, no doubt helped by being able to switch between the two truck manufacturers’ systems relatively easily.
Inter-brand platooning will be pivotal in Europe, it seems, because of the fragmented nature of the continent’s much smaller fleets than their stateside counterparts, Girteka Logistics running around 7,000 trucks compared to FedEx’s 25,000 in the U.S, for example. The EU’s ENSEMBLE project is the one to watch, focussed on interoperability between truck OEMs.
Although it is still maintaining its ENSEMBLE commitments, Mercedes-Benz Trucks was reported by Commercial Fleet13 as having “concluded that this is no business case for truck platooning, saying that the technology failed to deliver appreciable fuel savings in its on-the-road tests.” This is a shame, as we have been impressed first hand on several occasions by Mercedes’ technology such as Active Drive Assist and MirrorCam, but it’s fair to say that things can change quickly, so hopefully the manufacturer will re-join the platooning game at some stage.
The cited Forbes article concludes by asserting that the American market is more interested in long-distance fuel savings, while Europe’s focus when it comes to platooning is on sustainability and a reduction in CO2 emissions.
On the last day of April 2021, Freight Waves23 reported a ‘Setback for truck platooning as clock starts on Wi-Fi rule’, which is admittedly a challenge and indeed a disappointment purely affecting truck platooning projects in the States, but the UK, Europe and the rest of the world often owe a lot to pioneering endeavours initially made over the pond. Essentially, certain bandwidths had been reserved for V2X with road safety chiefly in mind, but a decision made during Trump’s reign has seen the Federal Communications Commission (FCC) nevertheless proceed with repurposing those frequencies for unlicensed public Wi-Fi use. Unsurprisingly, various voices in the U.S including Volvo are dismayed over the move, which ironically follows an increase in road fatalities during 2020, while the publication frustratingly states: “Regarding truck platooning, less available spectrum to work with could slow down progress and be costly for a type of autonomous operation that relies on V2X.”
The publication Fleet Owner24 quoted Michael Roeth from the North American Council For Fuel Efficiency (NACFE) as asserting that “platooning is a natural step in truck automation since it builds on the technology that is already being purchased on trucks”, a statement we would agree with based on the growing number of truck manufacturers incorporating ADAS such as automatic emergency braking, lane guidance and camera systems into their tractor units.
To us, Peloton’s product planning head is right that platoon operations in which human drivers still play a key role, mainly in driving the lead vehicle, will need to be driver-centric in order to achieve support.
April 2021 saw an article26 on SAE Mobilus reference Locomation’s recently having said that although driverless trucks are “tantalizingly close…the challenges that remain on the pathway to commercialization will keep the dream at bay for some time to come.” This sounds reasonable to us, as, despite huge strides having been made over in the automotive sector as a whole, including cars, so many factors will still hold up the arrival of autonomous vehicles operating freely amongst other traffic.
It’s fascinating to learn, then, that Locomation’s artificial intelligence (AI) projects have recently seen an autonomous truck successfully navigate sharp bends, strong gusts of wind and steep gradient inclines, which epitomise many parts of the UK. This was technically possible partly because of aerodynamic drag improvements and precise control of the vehicle by the autonomous driving system, with operating cost savings per mile touted as potentially high as 30%.
Despite WABCO (now a ZF brand) and other bodies pouring resources into addressing potential hazards and other safety aspects, we can’t help but agree with American trucking journalist Jack Roberts’ perception of platoons in that “it’s highly unlikely that these vehicles will operate without any human interaction – at least in our lifetime”27. Roberts also paints a vision that feels highly probable when he says that drivers will eventually perform pre-and-post-trip inspections, essentially providing reassurance for those in the road transport industry today that they will always play a vital role no matter what technologies, operational shake-ups and other changes come along.
Weighing everything up, it certainly seems likely that the U.S will get the first taste of real-world platooning, which will highly probably still involve human drivers sitting in cabs on standby for quite some years until proven safe in its own right, at which stage autonomous HGVs may take over follower duty. On the Continent, we can envisage larger countries such as France and Germany also perhaps seeing more sizeable fleet operators with hundreds of trucks and trailers increasingly trialling real-life platooning in limited forms on a relatively small number of routes. Here in the UK, though, the road network alone makes it hard to perceive platooning taking except in confined areas such as docks, ports and larger logistics and warehousing facilities, or on a handful of agreed motorway routes. Despite some truck manufacturers having backed away somewhat in recent times, it’s unarguably exciting that the road transport industry is still talking about platooning, though, with focussed start-ups stepping up their programmes, so Tiger Trailers’ team will definitely be keeping up with the twists and turns for the ultimate benefit of our customers.