Interest in sustainable trucking technology and fuels continues despite shifting U.S. federal support

Although federal support for clean‑transportation policies and funding has become more uncertain, momentum continues to build for alternative fuels, clean vehicle technology, and supporting infrastructure for commercial transportation, according to “The State of Sustainable Fleets.”

The annual market brief—written by TRC Companies Inc, a global environmental consulting and engineering firm—outlines the significant setbacks and challenges that the movement toward sustainable fleets has seen over the past year and a half. On the policy side, the report says that these setbacks included “the rollback of federal greenhouse gas (GHG) vehicle standards, the expiration of zero-emission tax credits for commercial vehicles, the cancellation of federal funding, and the nullification [by Congress] of California’s clean truck regulations.” At the same time, the cost for new trucks is rising due to tariffs and the need to meet upcoming Environmental Protection Agency (EPA) requirements for new engines. These costs and the continuing freight recession slowed demand for all types of trucks in 2025.

Despite these difficulties, support for clean commercial transportation has continued at the state, local, and utility levels. The report notes that available funding is still significantly above what it was five years ago. Additionally, fleet owners themselves continue to pursue a diversification strategy when it comes to the drivetrain technologies they use.

“Rather than retrenchment [into diesel drivetrains], we’re seeing interest and growth by fleets across a portfolio of solutions, so that they deploy each where it works best,” said Nate Springer, vice president of market developments for the clean transportation solutions team at TRC, during a media briefing about the report.

The report cites the following insights for each drivetrain type:

• Diesel vehicles: More than one-third of survey respondents said they are using fuel efficiency technologies—such as aerodynamic designs, engine improvements, and smarter transmission—as well as changes to driver behaviors to improve their fuel economy. Additionally, more than half of respondents say they are using renewable diesel (RD) and biodiesel (BD).
• Natural gas vehicles: New registrations of trucks and other commercial vehicles powered by natural gas dropped by 15% in 2025 compared to 2024. The report attributes this decline mainly to the freight recession rather than waning interest in natural gas technology. On the positive side, the report highlights the introduction of the Cummins X15N 15-liter natural gas engine, which delivers “diesel-like” power while cutting emissions and operating costs, and the increasing use of renewable natural gas.
• Propane vehicles: According to the report, the number of propane vehicles in operation increased year over year in 2025 by 3% and the market consumed 1.8 million more gallons of propane than it did in 2024. Fleet operators surveyed by TRC reported 39% operational cost savings on their propane vehicle operations as compared to vehicles they replaced.
• Battery-electric vehicles: New registrations of medium-duty and heavy-duty electric vehicles increased in 2025, but the report believes that this growth is unlikely to continue for medium-duty vehicles, such as delivery vans, due to the loss or reduction of key electric‑vehicle tax credits and ongoing infrastructure challenges. It notes that the Class 8 tractor segment was down in 2025 but shows signs of renewed growth.
• Hydrogen vehicles: While TRC notes that hydrogen technology is well-suited for heavy duty long-haul trucking, it warns that the long-term success of many hydrogen projects likely depends on sustained federal funding. Last year saw cuts to some hydrogen funding programs, and new registrations of hydrogen fuel cell electric vehicles dropped 12% compared to 2024.