The greenhouse gas measurement rule mandated that metropolitan planning organizations (MPOs) and state departments of transportation (DOTs) establish declining carbon dioxide targets and report on their progress. Specifically, these entities were required to set targets for reducing CO2 emissions generated by on-road mobile sources relative to a reference year defined as 2022. The original intent of the regulation was to help combat climate change by reducing greenhouse gas emissions from the transportation sector.

The trucking industry has expressed opposition to the greenhouse gas measurement rule, arguing that it imposed unnecessary burdens and complexities. Environmental groups, on the other hand, have criticized the repeal as a setback in the fight against climate change, emphasizing the importance of maintaining stringent emissions standards to protect public health and the environment.

With the final rule reversing the greenhouse gas measurement requirements, the regulation is officially struck from the record, with the rescission set to take effect on May 19. This move raises questions about the future of emissions standards and whether further regulatory changes will be implemented under the current administration. As the landscape of U.S. climate policy continues to shift, the implications for emissions reduction efforts remain uncertain.