Battery-electric vehicles dominate, with nearly all deployments falling into this category, while hydrogen fuel cell electric trucks remain limited to 155 units in the heavy-duty (HD) segment.
Zero-emission cargo vans account for 89% of all ZETs, yet yard tractors—while smaller in number—hold the highest market share within their segment at 2.82%. These vehicles are proving cost-effective and reliable, particularly in environments where short duty cycles and localized infrastructure enable rapid returns on investment.
Still, the pace of adoption slowed in the latter half of 2024, particularly for cargo vans, largely due to policy uncertainty ahead of the presidential election and inconsistencies in state-level implementation of the Advanced Clean Trucks (ACT) regulation.
California remains the leader with over 7,600 ZETs deployed, followed by Texas (5,009) and Florida (4,022). However, Maryland emerged as a standout in 2024, deploying 2,043 ZETs and growing its fleet by 439%—the highest percentage increase nationwide. States like Georgia and New Mexico also posted triple-digit growth, reflecting growing interest in regions beyond early adopters.
Notably, 39% of ZETs are deployed in ACT-adopting states, which account for only 27% of total truck stock. This reinforces how targeted regulations provide the market certainty needed to incentivize fleet and OEM investment.
Barriers to broader adoption persist. High upfront costs, financing challenges, and slow infrastructure rollout continue to hinder smaller fleets. CALSTART emphasizes a comprehensive policy toolkit: vehicle incentives, shared charging sites, utility-aligned infrastructure deployment, and state-backed financing mechanisms.
Some states are already responding. Maryland’s adoption of all seven “market dimensions” identified by CALSTART—including grants, ACT implementation, and strategic planning—has created an ecosystem conducive to investment and growth. Meanwhile, Texas and Georgia have demonstrated that private-sector investment and incentive programs can also drive deployment without stringent regulation.
The road to full ZET adoption is not without obstacles. While 2024 marked significant gains, the disparity in growth among states and declining median deployments reveal a concentration of progress in a few regions. Achieving a nationwide transition will require not only stronger policy alignment and public-private partnerships but also federal leadership to ensure all states have the tools and support to accelerate.
