The US Secretary of Transportation mentioned in testimony before Congress that even with low carbon fuels and more efficient vehicles, the US needs to work to reduce it's vehicle miles traveled (VMT). He states that even assuming 55mpg vehicles in 2030, the US transportation sector will only see modest CO2 decreases without a corresponding decrease in VMT.

He advocates for more mixed use development, more public transportation opportunities, more walkable and bikeable cities, and more housing development near public transit.