New research has found that federal regulations aimed at enhancing heavy trucks’ energy efficiency could be as much as 20% less effective than policymakers initially anticipated.
This is a result of regulations making heavy trucks cheaper. Therefore, more shippers will likely switch from using less energy-intensive rail transportation to using more energy-intensive trucks to ship goods.
“We were surprised to see how big of an impact the change in shipping decisions has on our energy use,” said Jonathan Hughes, the paper’s corresponding author and professor in the Department of Economics at CU Boulder.
“Increasing vehicles’ energy efficiency is very costly for truck makers, so it’s important to know how much benefit we can get realistically from these costly regulations.”
Heavy trucks are a huge contributor to harmful emissions
The freight sector, which includes the transportation of goods by truck, train, ship and aeroplane, represents around 10% of total US energy consumption.
Moreover, freight movement contributes to 27% of the country’s greenhouse gas emissions from the transportation sector, which is the largest source of emissions in the US.
The majority of freight sector emissions come from heavy trucks, which have increased their GHG emissions by 76% since 1990.
In a bid to reduce emissions and avoid the worse consequences of climate change, the US Environmental Protection Agency (EPA) has rolled out a series of regulations to improve heavy-duty vehicles’ energy efficiency since 2011. These rules require newly manufactured trucks to achieve better mileage using less fuel and emit less GHG.
In March, the EPA announced the strictest-ever fuel economy standards, aiming to prevent 1 billion metric tonnes of GHG emissions by 2055.
New regulations have seen an increase in freight movement
While these new regulations make heavy trucks more energy-efficient, they also make trucking cheaper by reducing fuel costs.
As a result, many shippers may opt to transport their goods by truck instead of rail because trucks can reach destinations faster, allowing for quicker product sales.
The authors note that trucks consume significantly more fuel than rail to transport the same amount of goods over the same distance, which has a rebound effect on the intention of the policies.
Unintended consequences
The researchers used newly released data on goods movement from the US Census Bureau to estimate the rebound effect in the freight sector.
Using a computer simulation, they calculated the amount of energy saved if the EPA regulations increased new trucks’ fuel efficiency by 5%, which is roughly what the standard is today.
Under this scenario, the team found that the regulations could potentially save 674 million gallons of fuel per year.
However, when they factored in the increased share of goods forecasted to be shipped by heavy trucks due to the rebound effect, the regulations would only save 497 million gallons of fuel—still a significant amount, but 26% less than previously estimated.
Accounting for all modes of freight transportation, the team estimated that the rebound effect in the freight sector would reduce the total fuel savings from federal regulations by 20%.
“We show that if we make transportation much more efficient, either through increasing energy efficiency or automation that reduces labour costs, we will likely wind up consuming more energy than we thought we would,” Hughes explained.
