Low-Carbon Fuel Standards Hit Snags Beyond West Coast States

A low-carbon fuel standard to cut vehicle emissions is moving ahead in Washington state but running into roadblocks elsewhere, leading some experts and opponents to pin blame on what they called a flawed policy.

Washington’s nearly $17 billion transportation plan (S.B.5974) signed March 25 makes it the third state—after Oregon and California—to implement a low-carbon fuel standard. Starting next year, fuel producers can earn credits for meeting steadily stricter carbon reduction targets, a policy that exceeds the national Renewable Fuel Standard with a wider array of gasoline and diesel beyond biofuels.

It’s the tool of choice advocates have pushed ...