Long combination vehicles offer much greater fuel savings and GHG reduction potential than platooned groups. Why is nobody talking about that? - Photos: Jim Park

Long combination vehicles offer much greater fuel savings and GHG reduction potential than platooned groups. Why is nobody talking about that?

Photos: Jim Park

I hope you'll forgive my naivety on this one, but I do not understand why we continue to pursue platooning when we already have a safer, more efficient, readily available and proven alternative: long combination vehicles.

LCVs can save 30% compared to two single tractor-trailers while two platooned truck can expect to save 7-14% compared to two single trucks. Turnpike doubles require one power unit and one driver, and require virtually no additional technical assistance to operate. The safety record for LCVs is irrefutable. Plenty of documented evidence exists from jurisdictions outside the U.S., such as Canada, that confirm their safety performance.

For all the meetings, demonstrations and lobbying in favor of platooning over the past eight years, had we redirected that energy and enthusiasm, we probably could have had a nationwide north-south and east-west LCV network in place.

Don't misunderstand me here. I'm not anti-technology. Technology is great, but technology for technology's sake isn't a good enough reason to pour resources into a solution for a problem that can be solved through simpler means – and with better results. LCVs are decidedly low-tech, but they work – and they are working in some form or another in 18 states. They safely log thousands of miles every day, saving thousands of tons of carbon dioxide.

Why Aren't Longer Combination Vehicles Widely Used in the U.S.?

So why are these vehicles not in much more common use?

We have the U.S. federal government to thank – the same government that has no objection to forcing untried, untested and expensive emissions technology onto trucks under the guise of reducing greenhouse gas emissions. If you think 2007 was bad, just wait 'till you see what's coming our way under GHG Phase II in 2022 and 2024. The complexity and cost of some of those proposed solutions is mind-boggling.

Back in 1991, Congress passed the Intermodal Surface Transportation Efficiency Act of 1991, which banned states from changing laws to allow the use of longer combination vehicles on the federal highway system. States that allowed LCV travel at the time were grandfathered and could continue to maintain their 1991 standards – including limiting them to 48-foot trailers rather than the currently more popular 53-footers. As a result, the use of LCVs on the federal-aid highway system could not be expanded beyond their then-permitted uses.

In icing LCVs under ISTEA, Congress cited concerns about safety and pavement damage. Granted, it was 1991 and people back then were not as sensitive to things like climate change and productivity and efficiency and congestion. What did hold sway on Capitol Hill was the vociferous lobbying of the railroad association and the so-called safety advocates – mostly truck crash victims and their attorneys who had axes to grind with the trucking industry.

That was nearly 30 years ago. There was a half-hearted attempt to reexamine the issue of longer and heavier trucks a few years ago, but Congress again folded its tent and went home saying there was not enough technical data available upon which to base a decision.

They didn't look very hard. And frankly, I don't think industry pushed all that hard, either. There is much evidence to support the development of LCV corridors around the country, and safety and pavement damage compare very favorably in every study you read.

One such study, "Longer Combination Vehicles: An Estimation of their Benefits and Public Perception of Their Use," published in 2012 by the National Center for Freight & Infrastructure Research & Education through the Department of Civil and Environmental Engineering at the University of Wisconsin, makes a very strong case for more widespread use of the longer combination vehicle.

So does "Long Combination Vehicle Safety Performance in Alberta 1995 to 1998," published in 2001 by John Woodrooffe & Associates. Even this project, Longer Combination Trucks, Potential Infrastructure Impacts, Productivity, Benefits and Safety Concerns, from 1994, published by the U.S. Government Accounting Office (now called the Government Accountability Office), indicates there are compelling reasons to look more closely at long combination vehicles, although some of the methodology – and thus the conclusions – are somewhat dated.

Bisin Transport is a 12-time winner of the Truckload Carriers Fleet Safety Award, and they make full use of LCVs on many Canadian freight lanes. -

Bisin Transport is a 12-time winner of the Truckload Carriers Fleet Safety Award, and they make full use of LCVs on many Canadian freight lanes.

Clearing Up the Myths

Pavement and Bridge Damage:

Some of the assumptions about pavement and bridge damage used in the 1994 GAO study were flat-out wrong, and the University of Wisconsin study says as much. LCVs do have higher gross combination weights (though they are still lighter than two comparably loaded five-axle combinations), but it's the axle loads that affect pavement life. And if the current rules are left in place, the axle weights would be no higher than we're allowed today.

According to the Wisconsin study: "Because LCVs carry more cargo and thus more weight than a standard truck, there is the perception by some that LCVs will naturally cause more pavement damage. However, this line of thinking is flawed, as the amount of pavement damage depends on the axle loads and the spacing of the axles. Therefore, an LCV may inflict less, more, or the same amount of pavement damage relative to a standard truck, depending on how much weight is to be carried, how many axles are supporting that weight, and how the axles are spaced."

In other words, we'd be no worse off than we are today, and I might add, no worse than we'd be with a pair of platooned vehicles, except that the LCV is 20,000 pounds lighter because it has only one power unit.

As for bridges, I'll be the first to admit I'm not an engineer. But I am a researcher, and I could find nothing conclusive about potential impact of LCVs on bridges. What's the difference if we have one legally loaded LCV on a bridge in one lane and two legally loaded 5-axle combinations following closely behind one another (like a platoon) in the adjacent lane? Which is likely to inflict more stress on the bridge?

Environmental Concerns:

This is a no-brainer: If there are fewer tractors on the road because the tractors are pulling multiple trailers, there will be fewer emissions of any description. Too often I think we mistake miles-per-gallon fuel economy with ton-mile efficiency. It's easy to see why an LCV would get poorer fuel mileage than a standard tractor-trailer, but we overlook that fact that we are moving twice as much freight with that fuel.

I interviewed several fleets that operate such trucks in Canada for a story I wrote last year on the economics of LCVs. They all said their fuel economy was in the 6.5-mpg range for LCVs (120,000 pounds GCW) and in the 8-mpg range for standard trucks (80,000 lb GCW).

To illustrate the point, here's a purely theoretical representation comparing the efficiency of the two types of vehicles:

5-axle tractor-trailer, 70,000-lb gross weight, 8.0 mpg

9-axle LCV, 120,000 lb gross weight, 6.5 mpg

Fuel consumed @ 300 miles: Two tractor trailers = 75 gallons; one LCV = 46 gallons

Ton-mile efficiency (tons x miles ÷ fuel): Two tractor-trailers = 280 ton-miles per gallon; One LCV = 391 ton-miles per gallon

GHG output: (22.38 pounds of CO2 per gallon): Two tractor-trailers = 1,678 pounds GHG; One LCV = 1,029 pounds GHG.

For those of you not doing your own math on this, that's a 38.6% improvement in fuel burned running two loaded trailers a distance of 300 miles. One of the fleets I spoke to on that story said that comparing two LCV units to four standard tractor-units on 171 LCV trips of just under 600 miles, his fuel savings was $53,865.

Of course, with that savings in fuel burned accrues a savings in the greenhouse gas emissions from those trucks – in the case of our mathematical example, a GHG reduction of nearly 40%. That in itself is nearly double what the U.S. Environmental Protection Agency and the Department of Transportation’s National Highway Traffic Safety Administration are hoping to achieve with GHG Phase II – and all we have added is a converter dolly.

Speed-limiters are on the radar screen, but proponents fail to consider in real-world implications, like taking three or four miles to complete a passing maneuver. -

Speed-limiters are on the radar screen, but proponents fail to consider in real-world implications, like taking three or four miles to complete a passing maneuver.


Long combination vehicles are not going to solve the driver shortage, but they could provide some relief.

Obviously, there are labor-cost savings to moving two loads with just one driver, but that driver would cost more by necessity. How much more would be a business concern, but fleets I have spoken with report increasing wages by $4 to $5 per hour or 10 to 15 cents per mile for LCV drivers. It depends on what the market will bear and whether drivers are keen to take on the extra responsibility. Some fleets reported having difficulty getting drivers to take on the challenge.

It would be reasonable to establish a set of qualifications for potential LCV drivers, something like a minimum of 5 years of experience and free of moving violations. That would ensure that only the best drivers are operating such equipment.


I'm proceeding here on the assumption that pavement and bridges along specified LCV network highways will not require significant upgrading, as axle loads will not change, as I noted above. There would, however, need to be some development of LCV staging areas at strategic locations along those routes. The New York Thruway, for example, has staging areas at nearly every interchange. Whether such areas would be developed by the public or private sector is a matter for discussion. Coalitions of carriers wishing to operate the more efficient trucks could co-fund such developments, or public dollars could build them, and usage fees could be collected to recover construction and maintenance costs.

Since these units would operate exclusively on interstate highways, there would be little need to upgrade existing arterial roads leading to the Interstates, except perhaps in industrial areas with high concentrations of trucking activity. There would be exceptions of course, but reasonable accommodation could be made to allow LCVs on such roadways if the infrastructure supported the wider turning radii required for the longer vehicles.

There was actually discussion in the GAO paper of the cost of having to build passing lanes on two-lane highways so motorists could get around the longer, slower trucks. That was just a smoke screen, I think, as few people would even consider allowing LVCs to operate off-interstate. That's the government for you.


This one is a little less definitive because there's almost no U.S. data breaking LCV crashes out of the larger numbers of truck crashes. And that hasn't changed since 1991 when Congress decided that safety was too big a concern to allow LCVs to mix with the general population. Congress didn't have any real data then either, but the safety advocates won that argument just on sheer volume.

However, research done in Canada in 2001 and again in 2016 indicates crash rates for LCVs in that country are significantly lower than for standard tractor-tractors.

Woodrooffe & Associates studied LCV crash rates in the province of Alberta from 1995 through 1998 and found just 30 collisions over that period. Only four collisions occurred on four-lane divided highways over nearly 30 million vehicle miles traveled. Three additional animal strikes were reported, and nine other events related to adverse weather or icy or wet pavement were reported. None of the crashes were attributed to vehicle dynamics.

Similarly, data from the province of Ontario covering a period from 2009 to 2016 show LCVs recorded 224,000 trips covering 43.3 million miles. There were eight reported collisions involving LCVs, but none of those accidents were the fault of the LCV driver.

Much of what little U.S. LCV crash data exists is based on modeling rather than actual crash reporting, it seems. Two studies, which can be found here and here, found that in some instances, LCVs experience fewer crashes per million miles of vehicle travel, but when gross vehicle weight is the denominator, vehicles have higher crash rates that standard 5-axle tractor trailers. That's a bit of a dichotomy, but when all overweight vehicles are included, the crash numbers no longer account strictly for LCVs. Frankly, much of the breakdowns and formulae used in those studies is well above my pay grade, but the executive summary provides enough of the whole story to garner a few clues about the results.

Carriers operating LCVs in established freight corridors can't capitalize on all the load-stacking opportunities because shippers refuse to be more flexible with delivery schedules. -

Carriers operating LCVs in established freight corridors can't capitalize on all the load-stacking opportunities because shippers refuse to be more flexible with delivery schedules.


Public Perception:

It was public perception that nailed the lid down on LCVs back in 1991, but it was just tha – perception. Safety advocates feared the longer, heavier trucks would be more deadly in a crash. While that might be true, a 40-ton 5-axle combo slamming into the back of a car would probably also kill all or some of the occupants. There are no degrees of dead, so let's be realistic about this. Trucks sometimes kill people in crashes, but LCVs are documented (in Europe, Canada and Australia) to be involved in far fewer crashes to begin with. The likelihood of being involved in a crash with an LCV is much lower, so that makes them a statistically safer bet.

The other issue often raised by motorists is the ability to pass the longer trucks. Oddly, much of what is written about this problem involves the fear of trying to pass an LCV on a two-lane road. That would shake me up too, but LCVs are interstate highway trucks and seldom if ever run on two-lane roads.

The other concern is freeway on-ramps. Motorists express concern about the big trucks impeding their ability to merge onto the freeway. The solution in Canada is to keep the LCVs in the second or third lane from the right (depending on the geometry of the highway), leaving the merge lanes open.

Officials in the province of Ontario for years resisted allowing LCVs on that province's four-lane limited-access highway network for fear of a public backlash. But when they finally did open the doors in 2009, there was no backlash. Officials got a few calls, naturally enough, but the fuss died down in a very short time and everyone has been getting along fine ever since.

This is purely anecdotal, but based on discussions with government officials; the LCVs have caused much less of a stir than the speed-limited trucks that annoyingly block both lanes on a highway while trying to overtake one another.

Parking Access:

Since LCVs are hardwired, so to speak, it's a bit harder to find places to park them. Some interchange configurations may not support them, either, but that would have to be sorted out when deciding on a dedicated LCV network of highways. This is where we get into assigning responsibilities and obligations.

Do we rely on public money to develop parking and staging areas for LCVs, or do the carriers that stand to benefit from their use cough up the cost? User fees perhaps? Many private sector truckstops could accommodate larger trucks, but certainly not all of them. Do we survey truckstops along designated routes and install signs identifying places for LCVs to stop? Would those truckstops even want LCVs on their lots? Parking isn't a big problem in New York, Pennsylvania, and Ohio, where turnpike rest areas are mostly drive-through affairs, but negotiating clover-leafs and looking for parking spots in truckstops (even dedicated drive-through spaces) could be challenging.


Ontario is an interesting test bed for LCVs that the U.S. could look at. The highway conditions and logistics environment closely mirror those of many major U.S. markets. The province opened a corridor from the U.S. border crossings at Detroit and Port Huron, Michigan, that extends all the way east to the province of Quebec (and further through Quebec and New Brunswick into Nova Scotia). Suddenly, carriers had consolidation opportunities they never had before. The past decade has shown huge LCV uptake on the part of retail distributors and LTL companies, but much lower uptake on the part of linehaul and truckload carriers.

You'd think the Detroit-to-Quebec corridor would be jammed with LCVs, but it's not, and there's a legitimate reason why.

"We can't always match the shippers' schedules," says one major carrier I spoke with. "Operations based on the truckload just-in-time model don't allow carriers to stack up trailers to haul down the road together. You leave when it's loaded and deliver on time. We could do a lot better with LCVs if we had more leeway on the timing and more cooperation from shippers on delivery times."

With the thousands of trucks that travel from places like Toronto and Montreal westward through Detroit and Port Huron, and back again, you'd think there would be opportunities for consolidation. There truly are, but there are logistical hurdles to get over, too.

"For this to work,, you need high volume, high frequency and highly recurrent activity," says the Toronto-based truckload carrier. "Going forward, we're going to need more engagement with the shipper. They will have to work with us and adjust schedules to make this work. They might not see any savings, but it might help them avoid some increases due to congestion or labor costs."

With that in mind, imagine the volumes of recurrent activity along corridors such as LA to Atlanta, Reno to Chicago, Detroit to Seattle or North Dakota to Mexico. Those corridors see thousands of movements every day heading generally in the same direction. The fuel and labor savings could be enormous if carriers could convince shippers to allow an extra day or so to manage the logistics of moving trailers through LCV assembly points.

Government Involvement:

Obviously the first step in resurrecting LCVs would be regulatory approval, and to get that trucking would have to build a pretty strong case – and now might be the time to do it. Various agencies are pushing trucking to reduce its carbon footprint, so if we hand them a plan for a 30% reduction of fuel consumption, how could they not listen? Those agencies have not been shy about mandating expensive and unproven (and generally unreliable) technologies to achieve 2% or 3% here and 4% to 5% there. And the cost to trucking of some of the yet-to-be-seen advanced emissions technology for 2022 and beyond will be shocking.

It would be difficult to ignore the safety-related improvements trucking has made since 1991, such as disc brakes, stability control, adaptive cruise control and automated emergency braking, to name just a few. Trucks are much safer today than they were nearly 30 years ago, and all of that technology could and should find its way onto LCV tractors.

It would be easy to establish lists of must-have safety technologies on LCV-tractors, but most trucks today are already equipped that way.

And perhaps some of those agencies so anxious to save the planet at trucking's expense could be convinced to spread a little of the regulatory pain around by encouraging shippers to adjust their schedules with a GHG tax or surcharge imposed on shipments that can't tolerate a day-longer delivery window. Perhaps shippers who opt for less carbon-intensive shipping practices could qualify for some sort of accreditation or include it in their climate-change initiatives.

I know that's a far-fetched list of stuff to hope for, but we've spent a lot of time and money testing truck platoons and we still haven't come to any firm conclusions. Many of the concerns with platooning are eliminated with LCVs. Not only do you eliminate the risk of a car sneaking in between the two trucks, you eliminate an entire tractor, and with it, its carbon footprint, labor, ownership and maintenance costs.

LCVs are an enigma to me. Simply put, they are safer, more fuel efficient, and more productive than any other combination out there. With all the push to reduce our carbon emissions, I can't for the life of me understand why this configuration remains overlooked. It's probably just because they aren't as sexy as a platoon, and frankly, that's not a good enough reason.

It might be a bit ambitions to even think about triple LCVs, but just imagine the fuel savings.

It might be a bit ambitions to even think about triple LCVs, but just imagine the fuel savings.


Jim Park
Jim Park

Equipment Editor

Truck journalist 13 years, commercial driver 20 years. Joined us in 2007. Specializes in technical/equipment material (including Tire Report), brings real-world perspective to test drives.

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Truck journalist 13 years, commercial driver 20 years. Joined us in 2007. Specializes in technical/equipment material (including Tire Report), brings real-world perspective to test drives.

View Bio