Effect of the Draft CAFE Standard Rule on Vehicle Safety


In August of 2018, the U.S. Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) released a proposed rule to replace existing vehicle fuel standards. Entitled, Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule for Model Years 2021–2026 Passenger Cars and Light Trucks, or the SAFE Vehicles Rule, the proposed rule would roll back requirements for fuel efficiency mandated in the Corporate Average Fuel Economy (CAFE) Standards. 

Synapse examined NHTSA’s and EPA’s vehicle sales and safety analysis, which is presented as a primary motivation for the selection of the standards in the draft rule. NHTSA and EPA estimate that lighter vehicles lead to more vehicle crash fatalities and automakers will be less inclined to reduce the mass of their vehicles if fuel economy standards are less stringent. Further, the agencies indicate that newer vehicles are safer, and more people will buy new vehicles under the draft rule instead of holding onto older vehicles because the cost to buy a new vehicle will be lower.

Our team conducted a literature review and reviewed NHTSA’s and EPA’s vehicle sales and safety modeling. Our analysis found serious flaws in the arguments and underlying analysis and assumptions used by NHTSA and EPA. After correcting these flaws, our analysis showed that increasing fuel economy and GHG standards maintains or even improves vehicle safety, consistent with peer-reviewed literature on this topic and past agency findings. Synapse released Effect of the Draft CAFE Standard Rule on Vehicle Safety, a report prepared for Consumers Union, in October 2018.

Project complete October 2018