EPA Skeptical About Safety Claims for Easing Emission Rules

The two federal agencies that formulated the Trump administration’s plan to freeze future fuel economy emission standards bickered repeatedly over assumptions made to justify the move, documents show.

The Environmental Protection Agency and National Highway Traffic Safety Administration submitted their joint proposal to the administration for review earlier this month.

But correspondence, draft documents and analyses released by the two agencies show repeated arguments about the models used to forecast the effect of the freeze, Bloomberg News notes. The skirmishing continued after the draft was turned over to the White House Office of Information and Regulatory Affairs.

One key assumption in the final proposal is that easing the regulations will reduce traffic deaths by about 1,000 per year. The rationale is that freezing the standards will keep new-car prices lower, thereby encouraging more owners of older cars to buy new and safer vehicles.

But EPA came to the opposite conclusion in mid-June after adjusting what it called “erroneous” and “problematic” assumptions in NHTSA’s mode. NHTSA countered that EPA’s assumption that neither the size nor number of miles driven by the country’s fleet would change.

EPA also advocated unsuccessfully to give carmakers more flexibility in meeting standards. The agency wanted to enable manufacturers to average fuel economy data for their entire fleets and give them more ways to earn credits for fuel-saving enhancements to their vehicles.