KEY FACTS

• Recent federal and state legislative efforts have sought to define long trains as those 7,500 feet or greater in length and to apply additional regulation to such trains.
• In 2025, the median length of a train on Class I railroads was 5,100 feet.
• Longer trains cut fuel use and emissions.
• Accident rates have dropped even as trains have grown longer.

There is no standard definition of a “long train.” Recent proposed legislation has sought to define a long train as one 7,500 feet in length or greater, and railroads have operated millions of trains exceeding that length without incident or notice for the past 80 years.

The industry’s safety record has improved even though trains are longer today. Since 2005, based on FRA data, the overall train accident rate is down by about 37% and the derailment rate is down by about 44%.

Long trains have operated safely for decades.

During the time that “longer trains” have operated, the industry’s safety record has dramatically improved. In 2025, the median length of a train on Class I railroads—meaning half were longer, half were shorter—was 5,100 feet. Just 10% of trains were longer than 9,500 feet and fewer than 1% of trains were longer than 13,400 feet.

The highly competitive freight transportation marketplace has increased pressures on railroads to become more efficient, and changes in the industry’s traffic mix have affected train length. For example, traffic mix plays a role in the length of trains in the network. A 100-car coal train is shorter than a 100-car intermodal train. In the past 10-plus years, coal traffic has declined by approximately 50% while intermodal traffic has trended higher.

Railroads are committed to safe operations no matter what.

While processes differ slightly by company, railroads consider several factors when determining the safe train makeup (how rail cars and locomotives are arranged) and train length. These factors include commodity mix, terrain, track conditions, layout, congestion, crew training, and more.

• Investments: Railroads have added new sidings and lengthened existing sidings on routes used for longer trains, which allow trains of various lengths to make way for other trains safely. The locomotive, car fleets, and track have been upgraded by freight rail’s capital expenditure and maintenance programs, which have averaged  more than $25 billion per year in recent years.
• Operations: Railroads review the characteristics of a route, incorporate lessons learned for the most effective operation of trains on that route, and confirm the safe operation by such measures as supervised pilot runs and modeling simulations that predict the performance of changes to a train’s makeup.
• Training: Railroads require training, both simulator-based and on-the-job, for in-cab technologies like fuel management systems, PTC, and distributed power. This includes adapting to changes in train composition or a crew’s introduction to new territories. The FRA mandates that locomotive engineers demonstrate proficiency on assigned routes, with annual railroad evaluations.

Technological advancements have improved safety.

Certain technologies have allowed railroads to operate longer trains more safely. For example, distributed power (DP) places locomotives throughout a train, not just at the front, all controlled by the lead engineer via a closed communication system. DP reduces in-train forces, improves handling on hilly or curved terrain, and allows faster, more even braking. Advanced algorithms also help optimize locomotive and car placement for better performance.

Moving fewer trains means less emissions.

The extra fuel consumption associated with limiting trains to 7,500 feet is the equivalent of around 640 Olympic-size pools. That’s about the annual emissions of roughly 930,000 cars. Moving a given amount of freight in fewer trains requires less fuel. Because GHG emissions are directly related to fuel consumption, longer trains mean reduced GHG emissions. That’s why capping train length is not environmentally sound.

AAR analysis of federal data finds: If 25% of the truck traffic moving at least 750 miles went by rail instead, annual greenhouse gas emissions would fall by approximately 11.4 million tons. Emissions would rise further if a cap on train length and the subsequent reduction in rail efficiency caused freight to divert to trucks, which are significantly less fuel efficient than rail.

THE BOTTOM LINE

While there is no single definition of a “long train,” most U.S. freight trains remain well below extreme lengths, and decades of data show accident rates declining even as trains have grown longer—reflecting continuous investment in safety, infrastructure, and operational practices.