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Updated March 4, 2022
Surface Transportation and Climate Change: Provisions in the
Infrastructure Investment and Jobs Act (P.L. 117-58)
Surface transportation is a major source of carbon dioxide
Figure 1. U.S. Greenhouse Gas Emissions by
in the atmosphere, one of the main greenhouse gases
Economic Sector, 2000-2020
(GHGs) contributing to climate change. The effects of
climate change, such as extreme heat and sea level rise, also
pose a threat to highways, bridges, and public transportation
infrastructure. Congress reauthorized the surface
transportation programs as part of the Infrastructure
Investment and Jobs Act (IIJA; P.L. 117-58). The IIJA
included mitigation policies and programs aiming to reduce
GHG emissions from surface transportation and adaptation
policies and programs aiming to make the surface
transportation system less vulnerable and more resilient to
the impacts of actual or expected future climate change. As
with previous authorization acts, the IIJA funded surface
Source: EPA, Draft Inventory of U.S. Greenhouse Gas Emissions and
transportation programs from the Highway Trust Fund
Sinks: 1990-2020, table 2-10.
(HTF). The IIJA also provided funding with a multiyear
advance appropriation from the Treasury general fund.
Several other current federal policies that seek to reduce
Transportation and GHG Emissions
GHG emissions from transportation are not typically
addressed in surface transportation reauthorization
The U.S. Environmental Protection Agency (EPA)
legislation, including the IIJA. This includes the regulation
estimates that since 2017, transportation has emitted more
of vehicle fuel economy by the Corporate Average Fuel
GHGs than any other sector of the U.S. economy. In 2019,
Economy standards administered by the National Highway
prior to the Coronavirus Disease 2019 (COVID-19)
Traffic Safety Administration and, by extension, the GHG
pandemic, transportation accounted for approximately 29%
standards, administered by EPA. These policies, along with
of the total (Figure 1). Total GHG emissions from
tax incentives and grants for the domestic development and
transportation were about 5% less in 2019 than in 2005, but
manufacture of alternative fueled vehicles, are typically
increased each year from a recent low in 2012 through
dealt with in energy bills rather than in transportation
2018, in part because of increased passenger travel and
legislation. Nevertheless, the IIJA contained energy
goods movement; the effects of greater vehicle mileage
provisions, including funding for a Clean School Bus
have been somewhat mitigated by improvements in fuel
Program administered by EPA. For more details, see CRS
efficiency. There was a slight reduction in transportation
Report R47034, Energy and Minerals Provisions in the
emissions in 2019, but a 14% drop in 2020 due largely to
Infrastructure Investment and Jobs Act (P.L. 117-58),
disruptions caused by the pandemic.
coordinated by Brent D. Yacobucci.
Mitigating GHG Emissions from
Surface Transportation
Surface transportation programs reauthorized in the IIJA do
in some respects encourage the deployment of alternative-
Economists generally agree that broad, market-based
fueled vehicles and a reduction of vehicle miles traveled.
policies, such as a cap and trade system or carbon tax, are
The Federal Transit Administration (FTA) Low and No
likely to be the most efficient way to reduce GHG
Emission Vehicle program provides funding for
emissions across all economic sectors. Motor vehicle fuel
alternatively fueled buses, and the Federal Highway
taxes might be considered a crude form of carbon tax in
Administration (FHWA) administers the Congestion
surface transportation, and the higher fuel taxes in other
Mitigation and Air Quality Improvement (CMAQ)
countries are associated with lower annual mileage per
program. The original motivation for these programs was to
person and greater use of more fuel-efficient vehicles. In
meet air quality goals, but such policies may help reduce
2020, the average of U.S. state taxes weighted by fuel
GHGs from surface transportation.
volume plus the federal tax on a gallon of gasoline was
$0.48. This compared with per-gallon taxes of $2.59 in
Adaptation to Climate Change in
Japan, $3.65 in the United Kingdom, and $4.57 in Italy.
Surface Transportation
Federal taxes on gasoline and diesel in the United States
Impacts from actual or expected future climate change are
have been collected largely to raise funds for infrastructure
likely to include higher average temperatures, greater
construction, not to control GHG emissions. The IIJA
extremes of temperature, more precipitation overall with an
extended through FY2028 the collection of the fuels and
increase in precipitation intensity and greater variation, and
other taxes that accrue to the HTF.
https://crsreports.congress.gov
Surface Transportation and Climate Change: Provisions in the Infrastructure Investment and Jobs Act (P.L. 117-58)
a rise in sea level. While the consequences of some of these
addition, the IIJA appropriated $13.2 billion annually for
changes may depend to some extent on other human
intercity rail programs for FY2022-FY2026.
activities, such as urban development patterns, they are
likely to include more frequent periods of extreme heat;
The IIJA also authorized and appropriated an increase in
fewer days below freezing; more coastal, riverine, and flash
funding for the federal highway program from $47.3 billion
flooding; and more droughts and wildfires. Intense
in FY2021 to an annual average of $73.1 billion for
precipitation could lead to more mudslides, particularly
FY2022-FY2026. This may result in more highway vehicle
following droughts and wildfires.
travel and GHG emissions, but the funding included
increases for new and existing highway programs aimed at
Existing surface transportation infrastructure can be
emissions reductions. For example, funding from the HTF
vulnerable to climate change because it was constructed for
for the existing Transportation Alternatives Program
sea level and weather extremes that are being or are likely
increased from $850 million in FY2021 to an annual
to be exceeded in the future. If the effects of climate change
average of $1.4 billion for FY2022-FY2026. New
become more pronounced, as studies anticipate, the impacts
mitigation programs and the average annual authorization
of extreme weather on surface transportation infrastructure
in the IIJA from the HTF for FY2022-FY2026 were:
and operations are likely to increase in magnitude, duration,
and frequency. For example, an increase in the number of
Carbon Reduction Program: $1.3 billion
very hot days could cause more damage to bridges because
Charging & Refueling Grant Program: $500 million
of greater thermal expansion of bridge joints.
Reduce Truck Emissions at Port Facilities: $50 million
“Adaptation” is action to reduce the vulnerabilities and
increase the resilience of the transportation system to the
Congestion Relief Program: $50 million.
effects of climate change. Adaptation and resilience options
include structural and nature-based engineering and policy-
New programs and the average annual appropriation from
based activities. For example, highway bridges can be
the Treasury general fund for FY2022-FY2026 in the IIJA
engineered structurally to withstand the threats of higher
were:
wind and water. Nature-based engineering may involve
reducing climate vulnerabilities through activities such as
Electric Vehicle Charging Formula Program: $1 billion
wetland restoration, artificial reef construction, and beach
Reduce Truck Emissions at Port Facilities: $30 million.
restoration. Policy-based activities include changing
maintenance practices, such as more frequent drain
Adaptation and Resilience
cleaning, and improving plans for weather emergencies.
The IIJA made several changes to the federal highway
program aimed at improving adaptation and resilience. It
Prior to the IIJA, FHWA had stated that federal highway
added definitions of “resilience” and “natural
funds could be used to assess the potential impacts of
infrastructure” to Title 23 of the U.S. Code. It specifically
climate change and to apply adaptation strategies. Likewise,
allowed federal funding to be used for “protective features”
federal transit funding administered by FTA could be used
designed to mitigate the risk of recurring damage from
for adaptation projects. Several aspects of federal law,
extreme weather events, flooding, or other natural disasters.
regulation, and policy required state and local agencies that
The IIJA also allowed states to use up to 15% of their
manage surface transportation assets to consider the effects
annual apportionment of National Highway Performance
of climate change.
Program funding for resilience features for highways or
Infrastructure Investment and Jobs Act
bridges that are not part of the National Highway System.
The IIJA made several changes to law and surface
The IIJA also established the Promoting Resilient
transportation funding programs for mitigation and surface
Operations for Transformative, Efficient, and Cost-saving
transportation infrastructure adaptation and resilience.
Transportation (PROTECT) Program to support adaptation
and resilience projects. Funding from the HTF was
Mitigation
authorized at an annual average of $1.7 billion.
The IIJA authorized and appropriated increases in funding
for public transportation and intercity passenger rail. Some
The IIJA also authorized Treasury general funds for some
advocates of these provisions assert that this funding could
new programs, subject to appropriations. This included
mitigate climate change. This assumes that greater spending
$100 million annually for Transportation Resilience and
will boost rail and bus travel, replacing trips by private
Adaptation Centers of Excellence, $100 million annually
motor vehicles and airplanes—something that has been
for the Healthy Streets Program, and $200 million annually
difficult to achieve in the past. Excluding COVID-19 relief
for the Active Transportation Infrastructure Investment
and other emergency funding, public transportation
Program. Healthy Streets Program grants would be to
program funding was $13.0 billion annually in FY2021,
construct pavement that reflects sunlight, to construct
whereas the amount authorized and appropriated in the IIJA
pavement porous to rainwater, and to expand tree cover.
was $21.4 billion annually for FY2022-FY2026 (unadjusted
for inflation). The Treasury general fund authorization for
William J. Mallett, Specialist in Transportation Policy
Amtrak and other intercity rail programs, subject to
appropriation, increased from $2.5 billion in FY2021 to an
IF11921
average of $7.2 billion annually for FY2022-FY2026. In
https://crsreports.congress.gov
Surface Transportation and Climate Change: Provisions in the Infrastructure Investment and Jobs Act (P.L. 117-58)
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
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https://crsreports.congress.gov | IF11921 · VERSION 3 · UPDATED