Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
However, the GHG reduction potential for heavy trucks or LCVs could be offset by its
impact on freight mode use. If the trucking industry is permitted to use heavier or longcombination
vehicles, the industry is likely to capitalize on its shorter, more direct, more
reliable, and faster routes between origins and destinations to capture 10 to 15 percent of
the current rail market (Martland, 2007). Rail is a more fuel efficient mode, so any
diversion from freight rail to truck would represent a negative GHG benefit.
To preclude the potential diversion from rail to truck, heavy or LCVs would need to be
allowed with specific restrictions to limit potential competition between truck and rail. In
general, a shipping container makes the long portion of its intermodal trip on a train and
is carried to the final destination on a truck. A dray move made by a truck that carries a
container from an intermodal facility or port to its final destination is not rail competitive.
In addition, natural resources can only be sourced on-location; a coal mine is the only
place to collect coal. There are specific natural resource sources that are only accessible by
truck via State highways and other truck routes.
Recognizing these factors, States could realize GHG emissions reductions in truck
dominant markets with little risk of rail competition by carefully structuring size and
weight permits to allow LCV trucks carrying natural resources in trucks that weigh up to
138,000 pounds on designated non-Interstate truck routes (to preclude long-distance
travel). In addition, Federal policy already allows overweight containers under special
permit, which can provide for trucks carrying shipping containers for distances less than
250 miles and weights up to a gross vehicle weight of 110,000 pounds (to improve port
and intermodal terminal access).
Magnitude and Timing of Greenhouse Gas Reductions
No comprehensive research has been conducted to evaluate the GHG reductions that might
be achieved from heavy trucks and LCVs. However, Moving Cooler developed some orderof-magnitude
estimates. Allowing trucks traveling on non-Interstate truck routes to carry
heavy natural resources in longer and heavier trucks (increasing the gross vehicle weight to
138,000 pounds) would save about 40 million gallons of fuel or 0.4 mmt CO2e. 27
Some
benefits already may be occurring since virtually every State allows overweight/oversize
trucks as long as the trucker pays the permit fee; allowing dray trucks to carry heavier
shipping containers from intermodal terminals and ports is estimated to produce annual
savings of 24 million gallons of fuel, or 0.2 mmt CO2e (Cambridge Systematics, 2009).
The benefits of lifting truck size and weight restrictions would likely accrue in two
increments. The first benefits would accrue very rapidly as the existing tractor trailer fleet
that already is able to haul heavy trailers is permitted and allowed to do so. The second
benefits would accrue over time as the remaining existing tractor trailer fleet—already not
able to haul heavy trailers—turns over and is permitted; the turnover rate for these trucks
is approximately 10 years.
27 The calculation reflects an 85 percent increase in productivity, and assumes that 25 percent of the
6.57 billion natural resource ton-miles would be carried by permitted heavy trucks.
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