The Bold New Era of California’s Advanced Clean Fleets Regulation

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California’s Advanced Clean Fleets (ACF) regulation, implemented on January 1, 2024, marks a significant step towards reducing emissions and promoting sustainable transportation in the state. 

This regulation aims to transition medium- and heavy-duty trucking to zero-emission vehicles (ZEVs) by 2045, aligning with California’s broader environmental goals. 

As we unravel the intricacies of this groundbreaking regulation, it’s important to understand its implications for fleet operators, the environment, and the future of transportation.

Table of Contents

Understanding the ACF Regulation

The ACF regulation is designed to complement the Advanced Clean Trucks (ACT) rule, which mandates an increase in ZEVs on California roads.

It targets a wide range of fleets, including high-priority, drayage, and public fleets, requiring them to incorporate ZEVs into their operations systematically.

This approach would ensure that all sectors of the trucking industry contribute to California’s emission reduction goals.

Scope of Application

A delivery person using his fleet management software on his phone as he exits the vehicle
Delivery person with phone gets out of the car

The regulation applies to:

  • On-road vehicles with a Gross Vehicle Weight Rating (GVWR) greater than 8,500 pounds
  • Off-road yard tractors
  • Light-duty mail and package delivery vehicles in fleets with 50 or more vehicles

Importantly, the ACF regulation affects not only vehicles registered in California but also those entering the state from elsewhere, considering them part of the California fleet for the entire calendar year they operate within the state. 

This broad scope ensures that out-of-state operators cannot circumvent the regulation, creating a level playing field for all fleets operating in California.

Key Components of the ACF Regulation

1. Drayage Truck Requirements

birdseye view of drayage on a port

Starting January 1, 2024, only zero-emission drayage trucks can be added to California’s fleet. Older drayage trucks must be retired at the end of their useful life, with the goal of making all drayage trucks zero-emission by 2035. 

This component of the regulation specifically targets port operations and short-haul trucking, areas where ZEVs can have a significant impact on local air quality and emissions reduction.

2. State and Local Fleet Requirements

By 2024, 50% of new truck purchases by local and state governments must be zero-emission. This requirement increases to 100% by 2027.

This aggressive timeline for public fleets sets an example for private sector adoption and helps create a robust market for ZEV manufacturers.

3. High-Priority and Federal Fleets Requirements

Fleets meeting specific criteria must comply with either:

  • Model Year Schedule: From 2024, fleets must purchase only ZEVs and remove internal combustion engine vehicles at the end of an 18-year useful life period starting January 1, 2025.
  • Zero-Emission Milestones Option: Fleets may choose to meet ZEV targets as a percentage of their total fleet, starting with vehicles most suited for electrification.

These options provide flexibility for fleets to choose the most suitable compliance pathway based on their operational needs and financial capabilities.

Compliance Pathways and Reporting

Fleets have two primary options for compliance:

  1. Model Year Schedule
  2. Zero Emission Milestone Phase-In Pathway

Each pathway has its own set of deadlines and requirements. The initial reporting for fleets was due by February 1, 2024.

This dual-pathway approach allows fleets to choose the option that best aligns with their operational realities and long-term strategies.

Reporting Requirements

Cities and fleet operators must submit annual reports on their fleet inventories to the California Air Resources Board (CARB). The initial annual report was due by April 1, 2024, with subsequent reports required within 30 days of adding vehicles to the fleet. 

These reporting requirements ensure transparency and allow CARB to track progress towards the regulation’s goals effectively.

Exemptions and Extensions

The ACF regulation includes several exemptions and extensions to accommodate various scenarios:

  • Emergency vehicles are exempt from the new rule
  • Lower populated municipalities with fewer than 10 medium-to-heavy duty vehicles are exempt until 2027
  • ZEV infrastructure delay exemption
  • ZEV purchase exemption
  • ZEV infrastructure construction extension for two years
  • ZEV infrastructure site electrification extension, up to three years until 2030

These exemptions and extensions recognize the challenges some fleets may face in transitioning to ZEVs, particularly in rural areas or for specialized vehicles. 

They provide a buffer for fleets facing genuine obstacles while still maintaining the overall trajectory towards zero emissions.

Impact on Fleets Nationwide

heavy duty fleet trucks parked

The ACF regulation affects any fleet conducting business in California, regardless of where they are based.

High Priority fleets, defined as entities owning or operating at least one vehicle in California and either generating $50 million or more in gross annual revenue or controlling 50 or more vehicles, must adhere to specific reporting and compliance mandates. 

This nationwide impact underscores California’s role as a trendsetter in environmental regulations and may influence other states to adopt similar measures.

Financial Incentives and Support

To ease the transition, various financial incentives and grants are available:

These programs are designed to support businesses of all sizes in adopting clean transportation solutions. 

By offering financial assistance, California aims to accelerate ZEV adoption and mitigate the upfront costs associated with transitioning to cleaner technologies.

Challenges and Opportunities

While the transition to ZEVs presents challenges, it also offers opportunities for long-term operational savings and environmental sustainability. 

Fleet managers must take a strategic approach, understanding specific requirements, evaluating compliance pathways, and planning vehicle acquisitions accordingly.

Infrastructure Development

One of the primary challenges in implementing the ACF regulation is the development of adequate charging infrastructure. Fleet operators must consider not only the acquisition of ZEVs but also the installation of charging stations at their facilities. 

This requires significant investment and planning but also presents an opportunity to reduce long-term fuel costs and maintenance expenses.

Technological Advancements

The push towards ZEVs is driving rapid advancements in battery technology, charging systems, and vehicle design. Fleet operators who embrace these technologies early may gain a competitive advantage as they become more efficient and cost-effective over time.

Workforce Training

Transitioning to ZEVs necessitates new skills for drivers, mechanics, and fleet managers.

While this presents a challenge in terms of training and education, it also creates opportunities for workforce development and new job roles in the green transportation sector.

Legal Challenges and Future Outlook

The ACF regulation faces legal opposition, with the California Trucking Association filing a lawsuit to block its implementation.

However, proponents argue that the regulation will yield significant public health and economic benefits, estimated at $26.5 billion in public health benefits and $48 billion in reduced costs for California fleets.

Environmental Impact

aerial view of a truck driving on a highway

The successful implementation of the ACF regulation is expected to significantly reduce greenhouse gas emissions and improve air quality, particularly in urban areas and near ports.

This aligns with California’s broader climate goals and sets a precedent for other states and countries to follow.

Economic Considerations

While the upfront costs of transitioning to ZEVs are substantial, proponents argue that the long-term economic benefits, including reduced fuel and maintenance costs, will outweigh the initial investment.

Additionally, the regulation is expected to stimulate innovation and job creation in the clean transportation sector.


California’s Advanced Clean Fleets regulation represents an important step towards a sustainable, zero-emission transportation future. 

While it poses challenges for fleet operators, it also presents opportunities for innovation and long-term cost savings.

As the regulation unfolds, collaboration between stakeholders, strategic planning, and leveraging available incentives will be key to successful implementation and achieving California’s environmental goals.

For fleet operators, staying informed about the regulation’s requirements, exploring compliance options, and planning for infrastructure development are essential steps in navigating this transition.

 As other states and countries watch California’s progress, the success of this regulation could have far-reaching implications for global efforts to combat climate change and improve air quality.

The coming years will be a critical period of adaptation and innovation for the trucking industry, with the potential to reshape the future of transportation across the nation and around the world.

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