A few weeks ago, I was being chauffeured down the A52 autobahn in Germany by a guy with no hands on the steering wheel as we sat just three or four car lengths behind another truck. At speed in a semi-autonomous Mercedes Actros sporting Daimler's cool Highway Pilot Connect system.

We were platooning, and it was pretty dull, really. While at the same time being damned exciting because it was cutting-edge technology at work.

It's supposed to be a dull experience, of course. Uneventful. Something's gone very wrong if there's any excitement at all.

There really was a distinct lack of drama in the process. In a platoon of three, I was in the third and last truck and was impressed by how seamless the electronic connecting and disconnecting of the three trucks was. If traffic demanded it, the trucks automatically disengaged and widened the gap, sometimes to allow merging traffic in, once to allow one of those pesky four-wheelers to live a little longer even though he rudely cut in between us and the next truck.

What is platooning? We're talking about technologies that create semi-autonomous road trains, where two or more trucks are controlled by a lead vehicle through wireless communication using about a billion sensors. (OK, I exaggerate -- in reality there are about 400 sensors on the Mercedes Actros tractors equipped with Highway Pilot Connect.) Trucks in such a convoy are able to drive very close together, reducing aerodynamic drag in a big way and bringing fuel-efficiency of as much as 20%, depending on which test you're looking at. The smaller the gap between vehicles, the better the fuel economy.

The trucks constantly maintain a communication link that allows them to share data and action. If the lead truck’s collision avoidance system activates its brakes, for example, the following truck or trucks will do the same.

The platooning idea has been around for ages, though you could be excused for thinking it's a new development, given all the attention it's been getting lately. It's not even close to being new.

The Beginnings of Platooning

In a very real way it can be traced back to 1939 when such things were the stuff of science fiction. But, as far as I can tell, that's when the idea for an automated car was born.

Back then American futurist Norman Bel Geddes, understanding that roads were just as critical as the cars themselves, imagined things like electronic speed and collision control systems and highways that went well beyond the norm and could be called "smart." He put his visions together for the Futurama ride that General Motors showed off at the 1939 World’s Fair. His ideas included, among many other spectacular things, magnetic trails built into the road to move and guide cars along. Platooning wasn't part of that imagined scenario, but you can easily see that it would fit. GM played with all of that in a more practical way with real experiments, especially the magnetic road, in the mid-1950s.

We got to platooning proper in 1972-73 with the European ARAMIS project, which had "trains" of as many 25 small transit vehicles running at about 50 mph -- just a foot apart -- using ultrasonic and optical range sensors. Only on a French test track, however.

And then there was, again in Europe, the Prometheus Project that ran from the late 1980s until 1995. It involved both car and truck makers, other technology companies, universities, and governments. The broad pan-Euro aim was to create intelligent vehicles within an intelligent road system that would encompass all the key areas like communications, vehicle control, and artificial intelligence. Mainly it was looking to produce driverless cars.

Volkswagen was involved in Prometheus and in 1989 they ran test-track trials with multiple-vehicle platoons at highway speed under full automatic steering and longitudinal control. The vans in the test were all automated, but we don't know much about the technology involved because it was and seems to remain proprietary.

VW dropped the project for political reasons, and next it was California’s turn, with an organization based at the University of California at Berkeley. PATH, the California Partners for Advanced Transportation Technology project, actually stretches back to 1986. And it remains active, a joint effort with state and federal governments.

The partnership was a platooning pioneer. In 1994 it showed an Automated Highway System that used automated longitudinal control of a four-car platoon. They ramped that up to an eight-car platoon in 1997. Not long ago it successfully operated several three-truck platoons at intervals of about 14 feet.

More recently we had SARTRE (Safe Road Trains for the Environment), another European Commission co-op project that ran from 2010 to 2012. Led by engineering consultancy Ricardo UK, its sole OEM partner was Volvo on both the car and truck sides.

Its goal was to develop strategies and technologies that will ultimately make platoons viable on public highways and bring environmental and safety benefits. The key difference here, I believe, is that it was the first such trial to use automated control in both lateral and longitudinal directions.

More importantly, it was the first such project to demonstrate platooning on public roads, in Spain. With the use of vehicle-to-vehicle communications (V2V), local vehicle signals such as speed and sensor data are shared among the vehicles in the platoon. The results clearly showed a benefit, with measured fuel savings of up to 20%.

Very significantly, this project's road train mixed trucks with cars. There was a manually driven lead truck followed by one truck and three Volvo cars. All the following vehicles were driven autonomously at speeds of up to 55 mph – in some cases with no more than a 13-foot gap between them.

The long-term vision is to create a transport system where joining a road train would be easy. To facilitate that, road-train information and operation will be integrated in future Volvo vehicles when the technology is ready for production. Booking, joining and leaving a road train must be easy and smooth, says Volvo.

Think smartphone. If you wanted to join a convoy in your car, you'd likely wait at an entrance ramp and your phone would "poll" passing vehicles to find one with a matching destination. Then you'd simply catch up to the "platoon" autonomously, your onboard sensors detecting the right vehicle ahead.

Waiting to find a platoon isn't going to work in a truck, because you could spend a lifetime catching up, so truck drivers would be rolling and polling at the same time.

Leaving the platoon would be easier still, your truck or car instructing you to take manual control and use a given exit. Any platooned vehicles behind you would simply close the gap automatically and the convoy would continue.

Interestingly, SARTRE people see the possibility of monetizing a platoon. Followers might pay a fee to join, with the lead vehicle earning an income for his trouble. What an interesting idea.

Newer Projects

Back on these shores, there's been a lot of interest in platooning over the last couple of years, much of it centered on Peloton Technologies, a Silicon Valley outfit that's been working with Volvo and Peterbilt and others. Volvo is an investor, as is Denso.

Peloton’s truck platooning system is an integrated safety, efficiency, and analytics platform that builds on advanced safety technologies such as collision mitigation and adaptive cruise control systems. The system electronically couples trucks through a combination of vehicle-to-vehicle communications (V2V), radar-based active braking systems, and proprietary vehicle control algorithms.

In 2014 Peloton, Meritor Wabco, and Denso staged a truck platooning demonstration in Detroit. It consisted of two driver-operated, electronically linked tractor-trailers equipped with Peloton platooning systems, Denso DSRC radios, and Meritor WABCO safety systems. They traveled along a stretch of highway at 55 mph separated by some 40 feet.

The trucks were linked by V2V that prompted the second tractor trailer to automatically accelerate or brake simultaneously with the lead vehicle as drivers maintained steering control themselves.

Peterbilt and Peloton have also done two-truck demonstration runs in Nevada and are looking to do more.

Platooning Benefits

A report on the first phase of research into the possible benefits of truck platooning technologies showed that all trucks in a platoon gained fuel efficiencies, with the lead truck gaining as much as 5% while the trailing truck got up to 10%.

The study was conducted by Auburn University’s GPS and Vehicle Dynamics Laboratory, along with partners Peloton, Peterbilt, Meritor-Wabco, and the American Transportation Research Institute.

As part of the Federal Highway Administration’s advanced research project on heavy truck co-operative cruise control, the first phase of the study looked at the commercial feasibility of "driver assistive truck platooning," or DATP.

Researchers gathered industry input for a preliminary case analysis and also looked at technical issues such as system modeling, aerodynamics modeling, research for developing algorithms for platooning formation, and human-machine interface evaluations.

According to the report released by ATRI, “the going-in hypothesis was that DATP technology is near market-ready for industrial use and will provide value in specific roadway and operating conditions for heavy truck fleet operations.”

DATP technology builds on adaptive cruise control, which has been available in the trucking industry for several years.

Some key findings:

  • Truckload and line-haul LTL operations would be the most likely fit for early adoption of DATP.
  • A majority of fleet managers contacted said such a system would have either a positive impact or no impact on driver retention and 39% said they felt drivers were likely to use a DATP system.
  • Owner-operators response was more toward the “negative end of the scale” the report said, and owner-operators would want a ROI payback within 10 months, while fleet respondents expected a payback within 18 months.
  • Using models based on historical traffic slows, researchers at Auburn found that platoon formation would not cost truckers excess time.

The “most challenging aspect,” of DATP, according to the report, comes down to who to platoon with. Most fleets would prefer platooning with their own trucks, while owner-operators would prefer platooning with other owner-operators, with only 7% of surveyed owner-operators willing to platoon with large fleets and 5% of large fleets willing to platoon with owner-operators.

Phase II of the study will focus on system testing using donated Peterbilt tractors equipped with the Peloton system and performance testing systems, specifically wireless communications, vehicle control, positioning, driver comfort and safety.

Europe's Platooning Challenge

Which brings us to today, almost literally. Last week six separate platoons formed by six European truck makers traveled, on separate routes along public roads, to Rotterdam in the Netherlands.

Invited to participate by the Dutch government, there were platoons from DAF, Iveco, MAN, Scania, and of course Volvo and Daimler. The three semi-autonomous Actros tractor-trailers I climbed around in Dusseldorf were part of this, the European Truck Platooning Challenge 2016.

Dutch organizers say the effort "aims to combine as many forces as possible to realize truck platooning in the near future. We will do this by creating a European partnership between truck manufacturers, logistics service providers, research institutes and governments – and by sharing knowledge and experience around truck platooning.

"We believe that truck platooning can become a reality in Europe in the near future.

"At the same time, realization will depend on bringing together member states and private parties with a view to crossing borders while harmonizing policies and technical issues. Close co-operation between significant partners in the truck industry, logistics services, research institutes and governmental can realize the ‘big picture’. Truck platooning will become routine.

"The Netherlands aims to make this close co-operation happen."

Realistic? Yes, I think so. Estimates about when we'll see it in action range from five years to 10, and I believe them. At least for over-the-road operations. Even the U.S. Army is getting ready for it.