CT DOT Seeks Permission to Resume Buying Diesel Buses

Connecticut’s transit agency wants permission to buy diesel buses again, two years after state law banned the practice in pursuit of a cleaner fleet.

The Connecticut Department of Transportation is seeking legislative approval to resume diesel bus purchases, citing a nationwide manufacturing backlog that has left the agency struggling to keep enough vehicles on the road. DOT officials made their case to lawmakers earlier this month, arguing that without the flexibility to buy some diesel buses now, the agency cannot replace aging vehicles fast enough to maintain current service levels for riders across the state.

Deputy Commissioner Laoise King put it plainly: without the ability to purchase additional diesel buses while the electric bus industry and its supporting infrastructure continue to develop, ConnDOT will not be able to keep pace with fleet replacement demands. King said the agency remains committed to reducing greenhouse gas emissions from transportation and is confident it can still meet a separate requirement to transition at least 30% of its transit fleet to zero-emission vehicles by 2030.

The agency’s proposed legislation, House Bill 5464, would lift the diesel ban while leaving that 30% zero-emission target intact. Connecticut currently operates more than 600 transit buses, including 61 fully electric buses and 77 hybrids. Under the existing law, the agency cannot even purchase new hybrids, which run partially on diesel, a restriction King said further limits the agency’s options.

The picture grew more complicated in written testimony from DOT Commissioner Garrett Eucalitto, who told lawmakers that battery recalls have hampered the performance of the state’s existing electric bus fleet. The state had been relying on federal funding to offset the higher cost of electric buses, but that money is now uncertain given shifting priorities under the Trump administration. Meanwhile, the limited number of domestic manufacturers has pushed wait times for new electric buses to as long as two years.

The push to lift the ban runs into the broader arc of Connecticut’s own clean energy commitments, and environmental advocates are not ready to concede the point. Lori Brown, executive director of the Connecticut League of Conservation Voters, called diesel engines “the absolute worst” in terms of sooty pollution and urged lawmakers and DOT to explore alternatives before abandoning the prohibition. Her argument carries a tactile force that any New Haven or Hartford commuter would recognize.

The agency’s request also arrives against a backdrop of missed targets. The Connecticut Clean Air Act of 2022, the same law that banned new diesel bus purchases starting January 1, 2024, set a goal of electrifying half the state’s fleet of smaller cars and trucks by January 1, 2026. The Department of Administrative Services, which manages that broader state fleet, acknowledged last year it was nowhere close to hitting that benchmark. A report released by DAS shortly after the deadline confirmed it had fallen well short.

That pattern matters here. Connecticut has now twice set ambitious vehicle electrification deadlines and twice watched agencies come back to the legislature with explanations for why the goals proved unreachable on schedule. The question for lawmakers is whether the manufacturing and funding constraints the DOT is describing reflect a genuine structural obstacle or a manageable problem that a little pressure and planning might solve.

The DOT’s position is that it is not walking away from electrification, just asking for more runway. King framed the request as practical rather than ideological, a bridge measure to keep buses running while the electric market catches up to the demand state policies helped create.

Environmental groups are not yet persuaded that the bridge is necessary, and they are right to ask whether there are alternative procurement strategies, federal partnerships, or fleet management approaches that have not been fully exhausted. The legislature will have to weigh whether the transit system’s operational needs justify reopening a door the state closed with real environmental intent just two years ago.

What is clear is that Connecticut’s electrification ambitions have run into harder friction than the 2022 legislature anticipated, and the consequences now fall on commuters, agency budgets, and the state’s credibility on climate commitments alike.