By Jeff Alson, Former EPA engineer who helped develop the Clean Car Standards, current consultant for EDF
The Trump administration is trying to justify its decision to roll back America’s Clean Car Standards — an action that will result in more pollution and greater costs for American families — by claiming that dirtier, more expensive cars will somehow be safer.
Yet the administration’s projection that the rollback will save lives has nothing to do with actual vehicle safety. It relies instead on unsupported assumptions about Americans’ driving habits.
Here are the reasons why the administration’s claim is extremely deceptive and deeply flawed:
The Department of Transportation’s own analysis demonstrates that clean cars are safe
The Trump administration implies that dirtier and less efficient vehicles are safer than cleaner and more efficient vehicles. Nothing could be further from the truth.
Even under the Department of Transportation’s (DOT) own analysis, there is no meaningful difference in vehicle safety between the Clean Car Standards and the proposed rollback. This finding is consistent with extensive evidence in EPA’s and DOT’s mid-term evaluation of the 2022-25 standards showing safety benefits associated with more efficient, less polluting vehicles using more defensible assumptions.
Essentially all of the 12,700 lives DOT claims would be saved by its proposed rollback result from DOT’s own unsupported assumptions about how the rollback will change the amount of driving Americans will do.
DOT has assumed that, in response to the rollback, Americans will voluntarily reduce the amount they drive – which will lead to fewer accidents and fatalities. Until now, DOT has always used the fatality rate — deaths per miles of travel — as its metric for the safety impacts of a program, not total fatalities. That helps ensure an analysis captures the effects of a proposed policy change on the risks associated with driving, rather than impacts based on assumptions about how much people will voluntarily choose to drive.
In multiple regulatory analyses over the last seven years, DOT did not report the effects of additional driving on fatalities in its safety analyses. Here, because nearly all of the reduced fatalities are due to DOT’s assumptions around reduced driving, the fatality rate is essentially unchanged between the current standards and the proposed rollback. Thus, under DOT’s standard metric, vehicle safety is unchanged.
For more detail, see the Preliminary Regulatory Impact Analysis, Tables 11-29 and 11-30. The cumulative values for fatalities and vehicle miles traveled in calendar years 2017 to 2050 show that the fatality rates are essentially unchanged between the current standards and the proposed rollback. They change by only 0.03 percent for the fuel economy analysis and by only 0.11 percent for the carbon dioxide emissions analysis. These insignificant changes in fatality rates suggest that at least 97 percent, and as much as 99 percent, of the reduced fatalities under the rollback are due to the Administration’s projected decrease in driving.
DOT exaggerates the reduction in driving new vehicles under the rollback by using an implausibly high “rebound effect”
About half of the decrease in driving that DOT projects under the rollback is due to the “rebound effect” — the economic theory that people will drive less if the fuel cost per mile increases. Under this theory, because the rollback of the Clean Car Standards will result in less efficient new vehicles that are more expensive to operate, DOT assumes that Americans will drive these new vehicles fewer miles compared to vehicles meeting the current standards.
In prior analyses, DOT assumed a 10 percent rebound value, an estimate recently corroborated by a comprehensive literature review that concluded, if anything, the value should be even lower. However, in analyzing the impacts of the proposed rollback, the administration indefensibly doubles that estimate, assuming a 20 percent rebound value. That means at least half of the reduced driving that the administration assumes will occur due to the rebound effect for new vehicles is an unsupported departure from current economic literature.
Quantifying the lower miles attributable to the rebound effect under the rollback has been challenging, due to gaps in the information DOT has provided about its methodology. Preamble Tables VII-88 and VII-89 suggest that rebound miles for the “lifetime of model years 2021-2026 vehicles” analysis for fuel economy are about 800 billion miles less and for carbon dioxide emissions are about 900 billion miles less than the current standards. In a very different “calendar year” analysis that assumes the rollback is carried out through 2050, Preliminary Regulatory Impact Analysis Tables 11-29 and 11-30 show that total miles traveled from 2017-2050 is about 2.7 to 3.3 trillion less under the rollback. DOT does not explicitly identify how much of this reduced travel is due to the rebound effect. Under the model year analysis, EDF believes that about half of it is due to rebound.
Though these estimates are themselves flawed, the way in which DOT presents them is also deeply misleading. In particular, DOT’s own analysis recognizes that reduced mobility comes at a cost to Americans, and that these costs offset the concocted safety benefits that the administration attributes to the proposed rollback. Yet the administration selectively touts the mythical safety benefits of the reduced mobility without mentioning that their own cost analysis cancels them out.
DOT modeling error projects decreased driving in older, used vehicles under the rollback
Though the Clean Car Standards only apply to new vehicles, DOT projects that their rollback will have a massive impact on how much Americans will drive older vehicles as well.
DOT assumes that if new vehicles become incrementally less expensive to purchase under the rollback, sales of new vehicles will rise, Americans will retire their older vehicles earlier, and the miles driven in those older vehicles will decrease by hundreds of billions of miles. That’s an amount far below the number of miles that the agency assumes will be driven in the newly purchased vehicles.
These assumptions are seriously flawed. First, new vehicle sales are not guaranteed to rise under the rollback. Though less efficient vehicles may be incrementally less expensive to purchase, those vehicles are substantially more expensive to operate — costs that quickly offset and ultimately outweigh the incrementally lower vehicle sticker price associated with the rollback.
More egregious is DOT’s inexplicable projection that Americans will drive their older cars hundreds of billions of miles less. This is a monumental modeling blunder. DOT and EPA have analyzed safety, fuel economy, and emissions regulations for more than 40 years, and neither agency nor any expert stakeholder has ever suggested a rationale that travel and mobility change in the older vehicle fleet — above and beyond rebound in new vehicles and potential sales impacts — due to the presence or absence of standards. DOT does not cite a single study of any kind that even speculates on such an effect, and does not offer any meaningful rationale for this incredible claim.
Quantifying these make-believe “lost” miles for older vehicles under the rollback in the various DOT rulemaking documents is challenging due to the inadequate information provided by DOT. Preamble Tables VII-88 and VII-89 suggest that these lost miles for the “lifetime of model years 2021-2026 vehicles” are about 700 billion miles less under the fuel economy analysis and about 900 billion miles less under the carbon dioxide emissions analysis. In the “calendar year” analysis that assumes the rollback is carried out through 2050, Preliminary Regulatory Impact Analysis Tables 11-29 and 11-30 show that total miles traveled from 2017-2050 are about 2.7 to 3.3 trillion less under the rollback. DOT does not explicitly identify how much of this reduced travel is attributable to the “lost” miles, but EDF estimates approximately one trillion miles, with the rest due to the use of an inflated rebound effect.
Economists at Resources for the Future’s recent blog said that DOT’s assumptions that the rollback would lead to lower overall vehicle miles traveled in the older car fleet were “inconsistent with economics” and that “we’re not aware of any real-world evidence supporting this argument.”
Yet a major portion of the administration’s claimed safety benefits from the rollback stem from this erroneous finding.
The bottom line is that rolling back the Clean Car Standards provides no meaningful safety benefit to the American people.