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Policy Tracker

Safer Affordable Fuel Efficient Vehicle Rule

Status:Final Rule Issued (Part 1)

What's the issue?

In August 2018,  the National Highway Traffic Safety Agency (NHTSA) and the US Environmental Protection Agency (US EPA) proposed the Safer Affordable Fuel Efficient (SAFE) Vehicle Rule. The proposed rule would hold the national fuel efficiency standard at the 2020 levels. The rule also proposes a "50 state solution" that repeals California's higher fuel efficiency standards, which were originally allowed to address California's unique air quality challenges.  If finalized, the rule would revoke California's authority to implement the Advanced Clean Cars and ZEV mandates.  Revoking these mandates will negatively impact the state’s ability to meet its greenhouse gas and criteria pollutant emissions reductions goals as well as public health, housing, equity, and goods movement goals.

What Does This Mean for TRANSPORTATION Projects?

In California, Metropolitan Planning Organizations (MPO) and Caltrans use a unique model (called "EMFAC") to demonstrate that each region and the state comply with the conformtiy requirements of the federal Clean Air Act. The current version of EMFAC assumes that ACC (I and II) and the ZEV mandate will continue to operate in California - resulting in cleaner cars.  If those standards are rolled back, the EMFAC model will not meet federal planning requirements to be based upon the "latest planning assumptions."

As a result, transportation agencies will be unable to demonstrate that their projects conform to federal Clean Air Act requirements. This means that MPOs and Caltrans (for rural non-attainment areas) will be unable to make new transportation conformity determinations for their RTPs, FTIPs, and amendments for projects not exempt from federal Clean Air Act requirements, as applicable.

What Regions Will Be Affected?

Areas that are defined as "non-attainment areas" will be affected, which is most of California.  A non-attainment area is geographic area that has air quality that is worse than the standards (called the National Ambient Air Quality Standard or NAAQS) that are defined in the federal Clean AIr Act.  Non-attainment areas must implement a plan to meet the standard or risk losing federal funding.   

  • MPO areas that are not in attainment:  Butte County Association of Governments, Metropolitan Transportation Commission, Sacramento Area Council of Governments, San Diego Association of Governments, San Luis Obispo Council of Governments, and the Southern California Association of Governments, and the entire San Joaquin Valley (Kern, Tulare, Kings, Fresno, Madera, Merced, Stanislaus, and San Joaquin Counties).

  • Other rural areas not in attainment:  Amador, Calaveras, Tuolumne, Mariposa, Mono, Tehama, and Plumas (some of these non-attainment areas may not have any current projects and therefore may not be immediately affected).

Consequences of Failing to Conform to the Federal Clean Air Act 

Due to many variables that can shape NHTSA/EPA final action, it is very difficult to determine what will happen next. But the general consequences of failing to conform to the act are described in the Act.  If an MPO in a non-attainment area fails to update its regional transportation plan at the required four year update cycle, a 12-month transportation conformity grace period starts; only projects in a previously conforming TIP can continue to be authorized by FHWA and FTA.  If the MPO fails to adopt an RTP that conforms to federal Clean Air Act requirements by the end of the 12-month grace period, the MPO lapses.  During a conformity lapse, only certain projects can receive additional federal funding or approvals to proceed (E-76 or federal permits), until the MPO has both a conforming plan and TIP.  This impacts regionally significant roadway and transitprojects (i.e. projects not-exempt from regional or project level conformity).  See below for those projects that can move forward during a conformity lapse.

  1. Projects exempt from conformity (regional and project level)
  2. Project phases that were approved before the lapse.
  3. Transportation Control Measures (TCMs) in an Approved SIP

Bottom Line

If California were required to follow the federal rollback proposal, global warming emissions could increase by almost 15 million metric tons per year by 2025. That is roughly equivalent to putting an additional 2.8 million cars on the state’s roads for a year. Emissions of nitrogen oxides (NOx), a key smog-forming pollutant in the state, would increase to 430 tons in 2030.

CALCOG estimates that just under 2,000 projects, totaling over $130 billion may face project delivery delays, or loss of funding.  Of that, roughly $22 billion may be at risk in the first six months should action be finalized by late Spring 2019.

What is the Solution?

It's uncertain.  And that is the problem. It is difficult to estimate how long it might take to update the EMFAC model and get it approved.  Moreover, each non-attainment area will have to update their SIP (the plan to meet National Ambient Air Quality Standards) in a way that takes into account the different mix of cars that will be operating in their area.  These types of actions can take as long as two years or longer. The best option - NHTSA/EPA rescind the proposed rule.

Key Dates to Watch

  • Final SAFE Vehicle Effective Date (unknown, but could be any time)
  • August 3, 2019: Deadline for MPO designated for ozone non-attainment for 2015 standard to receive federal approval
  • August 2019, CTC adopts STIP Fund Estimate (which often triggers need for TIP amendments)
  • December 15, 2019: RTIPS are due to California Transportation Commission
  • December 2, 2020: End of SANDAG conformity grace period.


  • June 2019 Proposed SAFE Vehicle Rule Update (CALCOG)
  • July 2019 Proposed SAFE Vehicle Rule Update (CALCOG)
  • September 2019 SAFE Vehicle Rule Update (CALCOG)
  • October 2019 SAFE Vehicle Rule Update (CALCOG)
More Info:Agency Website

Rule Making Information


CARB Transportation letter

  • CARB letter on transportation impacts.

17 Automakers urge nhtsa/epa & governor newsom to find middle ground

  • Automaker letter to President Trump
  • Automaker letter to Governor Newsom

Transportation California and California Laborers Join Opposition

California Briefing Information

Resources for Transportation Conformity

Last Updated:November 7, 2019