A study from the Canadian Trucking Alliance says it confirms that double trailer towing can reduce climate-change emissions and improve highway safety.
The two-year study compared data from 10 fleets that operate both single trailers and what is commonly referred to as a "turnpike double." Conclusions from the study say turnpike doubles:
- Are safer based on per-vehicle-kilometer-of-travel comparisons.
- Can save average of 28.8 liters of diesel per 100 kilometers of travel compared single trailers moving same volume of weight.
- Can reduce the number of trucks on the road by 6-10 percent.
All I can go on is information found in a news releases. Critics haven't responded or had time to review the study's data. But most motorists have an opinion on turnpike doubles based on their own experiences. From a strictly environmental standpoint, they make sense. They reduce the number of vehicles on the road, so there is a possibility that the overall effect is safer. But I've been to Australia a couple times and encountered "road trains" in the bush country, and it's absolutely frightening to see a massive tractor pulling three huge trailers coming at you on a two-lane road.
If they're kept on Interstates, turnpike trailers may have a legitimate role in helping reduce emissions. I would suggest that any diesel pulling a double trailer must be 2007 or later and running some form of biodiesel as a gesture that it's the cleanest possible method of transportation and an incentive to fleets to modernize their inventory and truck stops to offer biofuels. Despite the benefits, there will be considerable emotion playing into any regulatory decision that might open up more highways to double trailers or allow expanded use.