Standstill traffic on an eight-lane highway

Transportation Department's GHG Measure

In Jan­u­ary 2017, the Fed­er­al High­way Admin­is­tra­tion with­in the Trans­porta­tion Depart­ment pub­lished a rule com­mon­ly known as the GHG Mea­sure, under the full name Assess­ing Per­for­mance of the Nation­al High­way Sys­tem, Freight Move­ment on the Inter­state Sys­tem, and Con­ges­tion Mit­i­ga­tion and Air Qual­i­ty Improve­ment Program.”

The GHG Mea­sure required states, begin­ning in Feb­ru­ary 2017, to do the following:

  1. Track on-road green­house gas emissions
  2. Set local­ly-appro­pri­ate per­for­mance targets
  3. Ensure con­sis­ten­cy in data collection


The Trump admin­is­tra­tion has repeat­ed­ly attempt­ed to block the rule from com­ing into force.

  • May 2017

    In the spring of 2017, the Envi­ron­men­tal Pro­tec­tion Agency twice delayed the effec­tive date of the GHG Mea­sure until May 2017. The admin­is­tra­tion announced an indef­i­nite delay of the rule in May 2017.

  • Sep­tem­ber 2017

    In Sep­tem­ber 2017, eight attor­neys gen­er­al sued the Trump admin­is­tra­tion for unlaw­ful­ly delay­ing and sus­pend­ing the effec­tive date of on-road green­house gas emis­sions data require­ments. The law­suit prompt­ed the Trans­porta­tion Depart­ment to imme­di­ate­ly reverse course and begin to imple­ment required data col­lec­tion pro­ce­dures. The depart­ment sub­se­quent­ly pub­lished a notice of pro­posed rule­mak­ing to repeal the GHG Measure.

  • Novem­ber 2017

    Six attor­neys gen­er­al, led by Cal­i­for­nia Attor­ney Gen­er­al Xavier Becer­ra, filed com­ments in Novem­ber 2017 oppos­ing the pro­posed repeal.

  • May 2018

    In May 2018, the Trans­porta­tion Depart­ment issued a final rule that repealed the GHG Measure.