Design by Emma Sortor

A University of Michigan study found that a previous analysis conducted by the United States Postal Service (USPS) on the transition of the USPS fleet to battery electric vehicles (BEV) did not correctly approximate the potential benefits of the switch.

In their initial analysis in February, the USPS concluded that they would be purchasing 165,000 Next Generation Delivery Vehicles (NGDV) such that BEVs would make up 10% of their vehicle stock, while the other 90% would remain internal combustion engine (ICE) vehicles. USPS also updated this analysis in July to aim for 40% BEVs after re-estimating route optimization and improved infrastructure. 

Whether the USPS misrepresented greenhouse gas emissions from combustion engine vehicles was a source of debate between USPS and the United States Environmental Protection Agency (EPA). Environmental organizations such as the Sierra Club also raised questions on the accuracy of the statistics. School of Environment and Sustainability graduate student and the primary scientist on the paper, Maxwell Woody, said in an interview with The Michigan Daily that it was this dissent that was the original motivation behind the U-M analysis.

“The EPA, the Sierra Club, government organizations, as well as environmental groups, recognized some problems, and 16 states along with the District of Columbia have sued the USPS over this decision,” Woody said. “Once I took a look at the environmental impact statement, I decided that we could do our own independent analysis to try to verify or corroborate some of these claims.”

Woody said the U-M study uses more comprehensive experimental methods than the USPS study, such as quantifying vehicle life cycle emissions rather than only the emissions from the time that the vehicle is in use.  Additionally, the paper claimed the study’s method of calculating vehicle operating emissions was more accurate because of its use of fuel economy and fuel combustion intensity rates instead of per-mile emissions rates. 

The predicted amount of greenhouse gas emitted from USPS’ ICEs differed significantly between the U-M study’s findings and those of the USPS study, according to the report. The U-M study found that the USPS study underestimated the amount of carbon dioxide emissions that would come from using 90% ICEs in their fleet by 15%. They also found that the USPS study overestimated the emissions of a 100% BEV fleet by 8%.

Woody said he believes the mistakes made by the USPS study weren’t intentional, but rather an oversight on the part of the researchers.

“At the most basic level, they just selected vehicles from different modeling software that were not a good match for their actual vehicle and that led to some of these issues with the numbers that they used,” Woody said.

A representative for the USPS declined The Daily’s request for comment and stated that all relevant information will be available in the forthcoming Draft Supplemental Environmental Impact Statement (EIS).

On Aug. 16, President Joe Biden’s Inflation Reduction Act was signed into law. The act included $3 billion that could be put towards purchasing BEVs and installing infrastructure to support these vehicles. According to the U-M study, the increase in funding allows the USPS to potentially increase their commitment to switch their fleet to 90-95% BEVs.

Woody said this financial assistance should hopefully alleviate any barrier to the USPS fully electrifying their fleet.

“They have said that it would require about $3 billion more funding in order to fully electrify their fleet and with the Inflation Reduction Act, they have been given $3 billion more,” Woody said. “So the money is there. They’re running out of excuses for not electrifying a much greater proportion of their vehicles.” 

The U-M study also found that delivery vehicles like the USPS fleet are good candidates for electrification because of the nature of the post vehicles’ frequent stops and short routes. These characteristics help limit common barriers to implementing BEVs, including availability of charging stations on long-distance drives. 

Business graduate student Leo Lavigne, project manager for SPARK electric racing, said while he believes that the USPS delivery fleet would be a strong candidate for electrification, there needs to be a broader approach to decarbonizing the transportation sector.

“I think battery electric vehicles play an important role, but there certainly needs to be a lot of thinking about the underlying structure of how we do transportation instead of just saying battery vehicles fit everything, because there’s definitely also downsides,” Lavigne said.

Lavigne said the downsides to electric vehicles include the mineral demands for electric-powered batteries and water usage. 

Engineering senior William Jones, project manager of the U-M Solar Car team, said he thinks that electric vehicles make environmental sense for most government vehicles, not just the USPS fleet.

“I think it really makes sense for just about every single vehicle and government fleet to be electric. Everything from company cars (to) the police or USPS, because all of those routes are very well-defined,” Jones said. “There’s lots of facilities already in place; if you just transition those to electric, long term I think we’re going to save a bunch of money, not only in gas costs, but also maintenance on these vehicles.”

Daily News Reporter Isabella Kassa can be reached at