US Department of Transportation emphasizes a multi-pronged approach to reduce greenhouse gas emissions

The positive impacts of addressing any single priority for reducing greenhouse gas (GHG) emission could be of only marginal benefit without simultaneous efforts along other key priorities, warns the U.S. Department of Transportation (DOT). DOT Report to Congress: Decarbonizing U.S. Transportation lays out three strategies for reducing greenhouse gas emissions that DOT argues must be enacted in unison if the U.S. is to make significant progress in meeting its GHG emission goals. By way of example of why a holistic or coordinated approach is required, the reports notes that increases in vehicle driving and the movement of goods have canceled out the GHG emissions benefits of improved fuel economy in the US.

The report's data indicate that the transportation sector generates the largest portion (33%) of emissions in the U.S. DOT outlines three strategies deemed critical for reducing the sector’s share of the problem: increasing convenience, improving efficiency, and transitioning to clean options.

Increasing convenience involves designing systems to minimize the necessity of moving people and goods from one place to another. The authors suggest supporting active transportation and micromobility, improving land-use designs, managing parking demand, making fiscally responsible transportation investments, reducing goods movement by strategically siting warehouses, and using data tools, research, and technology for increasing convenience.

The authors say improving efficiency would redirect people toward more energy-efficient modes of transportation. Actions to improve efficiency include improving public and passenger rail transportation, investing in freight efficiency, and improving vehicle efficiency.

Transitioning to clean options involves “deploying zero-emission vehicles and fuels for all passenger and freight travel modes.” The authors suggest many actions, such as supporting the adoption of zero-emission vehicles, electric vehicles running on electricity from wind and solar, developing the supply chain and workforce to produce and maintain zero-emission vehicles, and using low-carbon construction materials and methods.

DOT has been funded to make progress to enact all three of the strategies. Of the $660 billion in transportation funding that the Bipartisan Infrastructure Law (BIL) authorized for DOT over five years, $27 billion is specifically for programs to reduce greenhouse gas (GHG) emissions, as reported by DOT in the report. Also as noted in the report, the 2022 Inflation Reduction Act (IRA) adds another $2 billion for a Low Carbon Transportation Materials Program.