Feeling Disconnected: Platooning has promise, but barriers remain
Posted: March 13, 2018 by John G. Smith
The idea of platooning trucks has been released to great fanfare, and for good reason. Double-digit fuel economy gains can be realized by allowing one tractor-trailer to tuck closely behind the next, drafting much like race cars as long as quick-acting safety systems are in place.
The concept is certainly closer to reality than the idea of fully autonomous trucks plying highways with drivers tucked away in their sleepers.
Pieces of the underlying technology work as advertised. I’ve had the chance to ride in cabs that automatically slam on their brakes if radar systems identify a threat in front of the bumpers; camera-based lane departure warnings help to keep everything between the lines. These systems promise reaction times that no human driver would ever match, clearly making them sound safety investments.
But I can’t help but see platooning itself as technology in search of a need.
Productivity gains and fuel savings can already be realized with long combination vehicles that pair 53-foot trailers behind a single tractor. Their required technology is also limited to things like higher horsepower; maybe a larger air compressor to ensure the rear trailer has the braking power it needs. Only a single driver is needed, too.
Then there’s the matter of how platooning would work in less-than-ideal settings.
Fred Andersky of Bendix Commercial Vehicle Systems, one of North America’s leading experts in collision mitigation systems, shared concerns of his own during the recent meeting of the Technology and Maintenance Council (TMC). At highway speeds, a lag in vehicle-to-vehicle communications could eat up three metres before the brakes begin to apply. Not only that, brake applications in the same tractor-trailer have been known to vary by eight to nine metres during the same test, he said. About eight to nine meters of stopping space can be consumed if the tractor-trailers incorporate different braking systems or maintenance practices.
This is all before we begin to consider the challenges of weather. Even a light cover of snow will increase stopping distances and obscure the lane markings tracked by camera-based lane departure systems. No platooning on those days, I guess.
Let’s, for the sake of argument, assume that you can find a pair of equally spec’d and perfectly maintained tractor-trailers. Those who dream of different fleets joining their equipment together in some sort of electronic tag team often gloss over the challenge of coordinating hook-up and departure times, or how willing that fleets with a trailing vehicle would share their higher fuel savings with the truck in front.
Don’t forget the human side of the equation, either. Few people seem to be discussing the stress that might emerge when tailgating another truck, staring at the same barn doors for hours on end. Potential productivity gains would also require changes to hours of service rules, offering more “driving” hours to those participating in the platoons to the rear. Just how long are we expecting these drivers to lock themselves inside before breaking off?
Yes, platooning can technically work. But there are plenty of operating realities to overcome. Maybe we should limit excitement to the benefits of underlying safety systems, and leave the drafting to NASCAR.