Revoking that waiver would tee up a lengthy court battle, and automakers are wary of the regulatory confusion that would follow. | Getty Images Trump administration to pare fatality reduction from car efficiency plan

The Trump administration will ratchet down its forecast of the number of lives that would be saved by rolling back the Obama vehicle fuel efficiency standards, an administration source told POLITICO.

The change would reduce one of the main benefits that the administration had touted in a rule change it proposed in August, and it comes after EPA and the National Highway Transportation Safety Administration got pushback for their estimate that 1,000 highway deaths would be averted annually by freezing the vehicle standards.


The two agencies are now revising assumptions used in the analysis that produced the figure in response to comments from experts criticizing their methodology. Chiefly, the agencies are reconsidering how long motorists hang onto their vehicles and how many miles they would drive with new, more fuel efficient cars. The interaction of those inputs would reduce the amount of avoided fatalities, the administration official said.

The agencies are also simultaneously negotiating with the California Air Resources Board over the implementation of national fuel rules, since EPA has said it planned to revoke California’s waiver to set its own more stringent tailpipe standards that are designed to fight pollution and climate change. Several other states also follow California's rule, bringing about 40 percent of the nation's vehicles under the stricter efficiency standard.

Revoking that waiver would tee up a lengthy court battle, and automakers are wary of the regulatory confusion that would follow.

Public comments have focused on the administration’s projections for the scrappage rate — essentially the turnover between old and new vehicles — and vehicle miles traveled. The Trump administration contended that requiring more fuel efficient vehicles would boost car costs and slow the fleet turnover to newer, safer models, and that people would drive more if their fuel economy improved.

EPA staffers challenged those conclusions in comments revealed through the interagency review process. Some contended freezing auto mileage standards at the 39 mile-per-gallon fleetwide average for model year 2020, as the Trump administration has proposed, would actually increase highway deaths. The Obama administration standards required the fleetwide average to reach 54.5 miles per gallon by model year 2025.

The administration official said the agencies are revising their forecasts for expected vehicle miles that would be traveled. Their original proposal envisioned an expanded national fleet without constraining how much motorists would use each car. But opponents rejected that analysis, saying the population of drivers and demand for driving are the key factors for determining vehicle miles traveled, not the number of cars on the road.

Critics said the agencies focused too much on price of new cars — ignoring, for example, that drivers hold onto their cars for longer now because they’re more efficient — and that its scrappage model was unrealistic and faulty. Some academics whose work EPA and NHTSA used to support its justifications have also said their studies were mischaracterized and misused.

EPA declined to comment, and referred questions to NHTSA, which did not immediately return a request for comment.

EPA and NHTSA reportedly clashed over some of the safety analysis prior to releasing the proposal. When asked whether he embraced NHTSA’s findings, acting EPA Administrator Andrew Wheeler said last week during a Washington Post event that the agencies “had a robust discussion” and that NHTSA has “the lead on highway safety issues.” And he defended the avoided fatalities as a justification for the rule.

“California is only looking at this issue under one policy agenda item, that is energy efficiency or climate change,” he said. “Our administration, we have multiple policy initiatives or policy reasons to move forward on the CAFE standard. One of the overarching ones is the lives saved and trying to get safer cars on the roads.”

Alex Guillén contributed to this report.