EPA Seeks Pre-Proposal Comments
on the Cleaner Trucks Initiative

United States. As of September 30, 2019, more than 128 million people lived in coun-
ties designated nonattainment for the ozone or PM2.5 National Ambient Air Quality
Standards (NAAQS), and additional people live in areas with a risk of exceeding those
NAAQS in the future. Reductions in NOx emissions will help areas attain and maintain
the ozone and PM2.5 NAAQS and help prevent future nonattainment.
Streamlining and Modernizing Heavy-Duty Emissions Regulations. EPA is actively
exploring opportunities to streamline our requirements, while ensuring no loss in protec-
tion for public health and the environment. For instance, we are working with industry
partners to develop a more cost-efficient path for manufacturers to demonstrate the
durability of their emission control systems. The ANPR describes several other areas that
EPA is evaluating for streamlining and modernization, and requests comment on addi-
tional opportunities we could consider.
Improving Real'World Emissions Testing. Today's in-use testing standards require
manufacturers to collect emissions data from heavy-duty vehicles on the road in the real
world. Our analysis suggests there may be great potential to improve in-use performance
by considering a broader range of engine operation when we evaluate in-use compliance.
The ANPR describes our current thinking on potential updates to the in-use testing
program and requests comment and data on all aspects of this topic.
Updating Laboratory Test Cycles for Heavy-Duty Vehicles. Based on our early analysis
of heavy-duty diesel engine technologies, we expect today's advanced diesel technologies
are capable of substantial emission reductions on current laboratory test cycles. We are
considering an additional laboratory-based test cycle that would evaluate an engine's
control of emissions during conditions not emphasized in today's test cycles, such as low-
speed, or low-load operation. The ANPR describes our current thinking and requests
comment on this topic.
Providing Additional Assurance of Emissions Controls through Extended Useful
Life and Emissions Warranty Provisions. Our current analysis shows that heavy-duty
engines operate well beyond EPA's current definition of the engine's regulatory full useful
life. EPA's current emission warranty provisions cover only a small fraction of an engine's
operational life. In order to ensure that emission controls continue to perform over a
period more reflective of the real-world operational life of heavy-duty engines, we are
evaluating longer mileage requirements for regulatory useful life and emissions warranty.
The ANPR describes our early thinking on this topic and asks for stakeholder input.
Working Towards a 50-State Approach for Heavy-Duty Vehicles. EPA is closely
following the technical work initiated by the California Air Resources Board (CARB)
to update their heavy-duty vehicle and engine programs under a Heavy-Duty NOx
Omnibus proposal. The ANPR provides an opportunity for comment on the extent to
which EPA should adopt provisions similar to those expected in the CARB Omnibus

Public Participation Opportunities
EPA welcomes your input on this Advance Notice. Comments will be accepted for 30 days
following publication in the Federal Register. All comments should be identified by Docket ID
No. EPA-HQ-OAR-2019-0055 and submitted at www.regulations.gov. For additional submis-
sion methods, please visit www.epa.gov/dockets/commenting-epa-dockets.
For More Information
You can access the ANPR and related documents on EPA's Cleaner Trucks Initiative
webpage at:
You can also contact the National Vehicle and Fuel Emissions Laboratory (NVFEL) Library
for document information by email at AALibrary@epa.gov or by phone at 734-214-4311.