Cutting big-rig emissions far easier said than done
Semis could slipstream to cut discharge of CO2 and nitrous oxide, says David Booth.
The fastest-growing source of transportation-based greenhouse gas emissions is not from the diesel-powered cars or gas-guzzling SUVs environmentalists love to revile. Nope, despite our desire for ever-larger cars and pickups, the biggest increase in CO2 emissions is from the transport trucks that deliver the goods we eat, sleep (in) and wear.
According to Environment and Climate Change Canada, in 1990, cars and trucks accounted for 71.1 megatonnes of carbon dioxide tailpipe emissions; 18-wheelers just 20.7. Fast forward 25 years and, while passenger cars now account for 83 megatonnes of CO2, the over-the-road transportation industry pumps out 63.2 megatonnes.
I’ll save you the math: While the cars and SUVs we drive now pump out 17 per cent more CO2 compared with 25 years ago, transport truck emissions have more than tripled.
Now, before you start an antitrucking Twitter war, know this: We are to blame for most of that increase. Truckers don’t drive for recreation or leisure. The main reason trucks are consuming more fuel is the Canadian consumer is buying and shipping more goods.
The Ontario Trucking Association (OTA) reports its members drove 70 per cent more kilometres in the same time frame, while in the U.S. the number of trucking miles driven has doubled since 1990.
Compounding the problem is that, in trying to rid the big rigs of nitrogen oxide emissions — down some 94 per cent, says John G. Smith, editor of Today’s Trucking — and those nasty diesel particulates that used to spew out of their stacks (also down about 90 per cent), those big diesels are now consuming more fuel.
Stephen Laskowski, president of the OTA, says diesel rig fuel consumption may be up as much as 10 per cent as a result of trying to clean up their tailpipes.
Like Volkswagen found in correcting its Dieselgate woes, compliance for one emission can mean an increase in another.
The reason all this might be of interest is that, according to Transport Canada’s Task Force on Vehicle Weights and Dimensions Policy Meeting, something called Cooperative Truck Platooning can dramatically reduce CO2 emissions.
The result of its Fuel Economy Testing of a Prototype 3-Vehicle Cooperative Truck Positioning System, platooning — the dark art of slip-streaming behind the truck ahead — can save up to 14.2 per cent in fuel consumption.
That’s a best-case scenario for a fully loaded 30,000-kilogram tractor-trailer streaming along at 105 km/h.
Even an empty truck noodling along at 90 km/h will see an almost eight per cent increase in fuel economy.
If three trucks maintained an even spread of 17 metres between them, there’s a good chance — fully loaded or not, cruising at 90 km/h or 105 km/h — platooning could reduce fuel consumption by as much as 10 per cent or 6.3 fewer megatonnes of CO2 released into our atmosphere.
That is roughly equivalent to the amount of greenhouse gases emitted by all the buses, trains and commercial passenger aircraft operating in Canada.
It would also be akin to every registered automobile in Canada consuming 0.8 fewer litres of gas per 100 km, which would be enough to reduce Canadian passenger-car greenhouse gas emissions to 1998 levels.
There are, of course, flaws. For one thing, a few truckers already platoon (though not as closely as Transport Canada’s experiment and, indeed, in some jurisdictions it’s illegal for truckers to slipstream within 17 metres).
For another, some of the CO2 those freight trucks spew out occurs in urban areas where it is neither practical, useful, nor safe for multiple trucks to follow one another close enough.
That said, I suspect the main impediment against formalized — or even mandatory — platooning will probably be social.
For safety’s sake, having trucks maintain such a close distance for such long distances would require sophisticated automated cruise control systems. Furthermore, to maximize the amount of platooning, trucks across North America would have to “talk” to one another — the much-lauded vehicle-to-vehicle (V2V) communication that is part of our proposed autonomous future — so destinations, routes and speeds could be co-ordinated for maximum platooning.
The problem is, cruising semiautonomously and the ability to interact automatically with the infrastructure and other vehicles is but a small hop, skip and jump from the fully autonomous future threatening to put some three million North American truckers out of work.
As with everything about the reduction of tailpipe emissions, there are few simple answers.
A note from the author: For those wondering why we’re using more fuel — that 17 per cent increase in CO2 emissions from 1990 to 2015 — despite the advancements in technology, the reasons are twofold. For one, we’re simply driving more cars. There were 15.3 million passenger vehicles registered in Canada in 1990, and 25.5 million driven today. More troubling, however, is that while the efficiency of the engines powering our cars has improved, consumers have compensated by buying bigger vehicles. So, while the University of Michigan’s Transport Research Institute notes the average vehicle’s fuel economy has improved by some 20 per cent since 2007, we have only reduced our carbon footprint by about two per cent.