Shapiro Administration Moves to Rescind Pennsylvania’s Heavy-Duty Diesel (CARB) Rule
In a significant development for Pennsylvania’s trucking industry, Governor Josh Shapiro’s January 31, 2026 Regulatory Agenda includes formal plans to rescind the Commonwealth’s Heavy-Duty Diesel Emissions Control Program (25 Pa. Code Chapter 126, Subchapter E) — the rule PMTA has been challenging in court.
This action represents a major milestone in PMTA’s multi-year advocacy effort opposing Pennsylvania’s adoption of California's heavy-duty emissions standards.
What the Regulatory Agenda Says
The Governor’s 2026 published regulatory agenda indicates that the Environmental Quality Board (EQB) intends to pursue rulemaking to rescind the Heavy-Duty Diesel Emissions Control Program.
Heavy-Duty Diesel Emissions Control Program Rescission – 25 Pa. Code Chapter 126
Quarter 3, 2026 – EQB Consideration (as Proposed)This rulemaking proposes to rescind Pennsylvania’s Heavy-Duty Diesel Emissions Control Program (PA HDD Program), 25 Pa. Code Chapter 126, Subchapter E, because it has become unnecessary.
This is the very regulation PMTA challenged due to its economic impact, legal concerns, and reliance on California’s regulatory framework.
While regulatory agendas are not final actions, this represents a clear signal of policy direction. The decision to rescind, rather than merely suspend enforcement, carries broader significance.
Why “Rescission” Matters
In its regulatory agenda, DEP states that the Heavy-Duty Diesel Emissions Control Program is being rescinded because it has become “unnecessary.” That assessment is likely tied to recent federal developments affecting California’s emissions framework, which have made CARB's regulations unenforceable in other states at this time.
However, rescission is more significant than simply acknowledging current federal constraints. If finalized, rescission would:
- Eliminate Pennsylvania’s existing regulatory framework tied to California’s Low-NOx standards
- Prevent automatic revival if federal policy shifts in the future
- Require any future heavy-duty emissions program to undergo a new, formal rulemaking process
- Ensure legislative oversight and stakeholder engagement before similar standards could be adopted again
In short, rescission closes the chapter on this rule rather than simply placing it on pause. That provides regulatory certainty for Pennsylvania carriers and equipment purchasers moving forward.
Recognizing Our Legal Partner
PMTA’s legal challenge would not have been possible without the dedicated representation of Pacific Legal Foundation, which has represented PMTA throughout this litigation.
Pacific Legal Foundation is a nationally respected public-interest law firm that litigates cases involving constitutional structure, separation of powers, and regulatory overreach. Their commitment to defending accountable governance and protecting economic liberty has been instrumental in advancing PMTA’s case.
We are deeply grateful for their partnership, expertise, and belief in the importance of this issue to Pennsylvania’s trucking industry.
Why This Matters
If it continued to link PA to extreme California low-NOx regulations, the Heavy-Duty Diesel rule would have:
- Tied Pennsylvania to California’s Low-NOx Omnibus standards indefinitely
- Increased truck costs significantly
- Created uncertainty in equipment purchasing decisions
- Risked limiting product availability
- Added compliance burdens for trucks registered in Pennsylvania
PMTA consistently argued that:
- Pennsylvania should not outsource its truck emissions policy to California
- Implementation was flawed and lacked adequate economic analysis
- Legislative oversight had been bypassed
- Pennsylvania businesses deserved transparency and accountability
Our legal action paused enforcement and preserved options for carriers while this debate unfolded.
Does This Mean PMTA “Won”?
Though it's important to note that nothing is final until the Commonwealth's rule is published, if the EQB follows through with formal rescission, it would effectively resolve the rule in alignment with PMTA’s position.
However:
- The rule is not officially rescinded yet.
- Formal rulemaking must still proceed through the EQB process.
- Public comment and administrative procedures will still occur. PMTA will inform members when it's appropriate to weigh in with comments during this process.
PMTA will remain actively engaged to ensure the rescission is completed and that future emissions policy is developed transparently, with legislative input and stakeholder engagement, including from PMTA and its members.
The Bigger Picture
This development reflects what sustained, professional advocacy can accomplish.
Over the past several years, PMTA worked with members to:
- Raise concerns early about CARB adoption
- Collaborate closely with legislators
- Elevate economic impact concerns
- Communicate directly with DEP and the Governor's Office
- Pursue litigation when necessary
- Keep members informed throughout
Advocacy requires persistence. Sometimes it requires litigation. Often, it requires patience.
This appears to be a moment where that persistence is paying off.