LOCOMOTIVES Act Blocks States From Setting Stricter Pollution Rules for Existing Trains

The newly proposed Lifting Overburdensome Commerce Obstructions and Motives Act—the LOCOMOTIVES Act—is laser-focused on one thing: taking the steering wheel away from states when it comes to regulating pollution from trains and certain heavy equipment. This bill amends the Clean Air Act to significantly expand federal control, effectively preempting, or overriding, state and local emission standards for older locomotives that are already in use.

The Federal Takeover of Train Emissions

Right now, states have some ability to set their own, potentially tougher, pollution standards for certain types of engines, especially older ones. The LOCOMOTIVES Act shuts that door for trains. Specifically, Section 2 is designed to ensure that federal rules apply across the board, even for locomotives that become subject to new federal regulation in the future. Crucially, it adds a new category (subparagraph C) that ensures federal preemption applies to virtually all existing locomotives “engaged in commerce.” This term is defined broadly, covering pretty much any train that hauls freight or passengers for pay.

What This Means for Your Air Quality

So, why does this matter if you don't run a railroad? Because locomotives—especially older, diesel-powered ones—are significant sources of air pollution, including nitrogen oxides and fine particulate matter, which contribute to smog and respiratory illnesses. If you live near a major rail yard, a busy freight corridor, or an industrial area, that pollution is part of your daily life. Currently, some states and cities have tried to mandate cleaner technology or stricter operational rules for these older, dirtier engines to protect local air quality.

This bill pulls the rug out from under those local efforts. If the federal government’s standard is weaker or slower to update than what a state wants, the state is now legally barred from forcing railroad companies to clean up their act sooner. The benefit for the railroad industry is clear: they get regulatory uniformity and don't have to retrofit their aging fleets to meet 50 different state rules. The cost, however, is borne by residents in those rail-adjacent communities who lose their local government's ability to demand cleaner air.

Small Engines Get Swept Up Too

The bill also cleans up some language around smaller nonroad engines, those under 175 horsepower, often found in construction or farm equipment. It clarifies that federal preemption applies to these small engines only if they are already regulated under the Clean Air Act. While this sounds like a technical fix, the main thrust of the entire section is consolidation of power: centralizing emission authority for these heavy-duty engines—from tractors to trains—at the federal level. For busy people, the impact is simple: if you were counting on your state or city to push for cleaner train engines to improve local air quality, this bill is designed to stop them cold.