States That Adopted California Truck Emissions Rules Seek Leeway

Some states are second-guessing when and how to enforce the zero-emission truck quotas and tailpipe emissions standards they adopted from California years back, citing market pressures and tight compliance timelines.

Four states have taken steps to delay the rules—which would increase the number of zero-emission trucks delivered for sale and limit emissions from remaining trucks—after some trade groups said it would be difficult to comply.

“We’re at the stage of testing, not at the stage of full adoption” for the zero-emission truck industry, said Jacqueline Gelb, vice president of energy and environmental affairs at the American Trucking Associations. “The demand ...