MDOT Greenhouse Gas Reduction Act (GGRA) Plan 

Appendix J of the Maryland 2030 GGRA Plan  


In 2009, Maryland adopted the Greenhouse Gas Emissions Reduction Act (GGRA) and it was amended in 2016. The law requires the State to reduce GHG emissions 25 percent from a 2006 baseline by 2020, in a way that ensures a positive impact on Maryland's economy, protects existing manufacturing jobs and creates new jobs in the State. The Maryland Department of the Environment’s (MDE) 2015 GGRA Plan update showed that Maryland was on target to not only meet but also to exceed this level of emissions reduction in tandem with a healthy economic benefit.

Governor Hogan signed an updated version of the law, which includes the same balanced requirements and safeguards as the original, such as additional reporting and a mid-course reaffirmation of goals by the Maryland General Assembly, as well as incorporating protection for jobs and the economy. The most significant enhancement was a new benchmark requiring a 40 percent reduction of emissions from 2006 levels by 2030 (“40 by 30”). This additional benchmark was included in order to ensure continued progress after 2020 toward the State's long-term GHG emission reduction goals. According to a World Resources Institute report published in August 2020, Maryland leads the nation in the amount of emissions reductions (38%) and simultaneous growth of GDP (18%) in a 12 year period. For more information, visit Maryland’s GGRA.


The GGRA requires the MDE to submit a plan that reduces statewide GHG emissions by 40 percent from 2006 levels by 2030. MDOT worked in coordination with MDE, other agencies, and partners to develop and test strategies for the transportation sector to achieve the “40 by 30” goal. The 2020 Maryland Department of Transportation (MDOT) GGRA Plan [LINK – There will be 3 links: Plan, Appendix A, Appendix B] presents MDOT’s approach to meet the requirements of the GGRA.

The current statewide emissions inventory, developed for 2017, shows that on-road transportation is the single largest GHG emissions generator in Maryland, representing 36 percent of total GHG emissions. Off-road transportation (aviation, marine, and rail) represents another 4 percent.

Statewide VMT, which is a major indicator of transportation sector GHG emissions, has been steadily increasing in Maryland since 2014, with over 60 billion VMT in 2019. VMT growth has been consistent with population growth as VMT per capita has remained stable. While population increase is expected to create additional demand for the State’s transportation systems, VMT in Maryland dropped dramatically in 2020 due to the COVID-19 pandemic. Based on MDOT’s estimates of VMT trends, 2020 annual VMT is expected to drop to an estimated 51.1 billion VMT statewide. While MDOT anticipates that VMT will rebound back to 2019 levels over the next five years, there is uncertainty regarding the exact timeline and pace of the recovery.

A steady increase in transportation demand indicators including growth in population, vehicle miles traveled (VMT), and congestion combined with limited revenue relative to needs creates a major challenge. Based on MDOT analysis accounting for these challenges and by harnessing new opportunities, it is possible for Maryland’s transportation sector to meet the “40 by 30” goal. The analysis considered two policy scenarios built from the Maryland Transportation Plan (MTP), the Consolidated Transportation Program (CTP), and Maryland’s two major Metropolitan Planning Organizations’ (MPO) plans and programs (Baltimore and Washington D.C. regions). Achieving the goal will not be easy and requires an innovative and cost-effective approach that includes:

  • An aggressive investment in transportation beyond current levels of projected funding,
  • Supportive policy and new and additional resources enabling MDOT to fund and advance these needed investments,
  • A shared commitment and coordinated approach between MDOT and its partners to advance reliable, low-cost, and low-carbon technologies, and
  • A best-case scenario for the roll-out and adoption of transportation technology, including market penetration of electric vehicles (EVs) into public and private fleets in Maryland.

MDOT is a member of the Maryland Commission on Climate Change and is a participant in its four Work Groups.

MDOT Climate Change Status Reports