Freight rail is well ahead of other modes of transportation when it comes to limiting greenhouse gas emissions, increasing fuel efficiency and reducing its carbon footprint.
From advanced locomotive technology to zero-emission cranes, freight railroads use technology in all aspects of their operations to preserve the environment and help mitigate climate change. Thanks in part to these technologies, today U.S. freight railroads can, on average, move one ton of freight nearly 500 miles per gallon of fuel, making rail an environmentally friendly way to move freight over land.
Maximizing Fuel Efficiency
Railroads use advanced computer programs, known as fuel management systems, to ensure that each gallon of fuel moves a train as far as possible. The systems, fully integrated into the trains’ locomotives, provide engineers with real-time recommendations on how to operate the train to maximize fuel efficiency and train performance based on numerous variables including topography, track curvature, the weight and length of the train and even wind effect. Fuel management systems can improve fuel efficiency by up to 14%, depending on the route.
The most advanced diesel locomotives, known as Tier 4 locomotives, make freight rail even more environmentally friendly. Today’s Tier 4 locomotives have hundreds of sensors that generate thousands of readings on locomotive performance every minute. The diesel engine alone has 50 sensors, which monitor a variety of factors, including engine speed, valve control and air/fuel mix, to continuously maximize fuel efficiency. These readings are monitored in operations centers across the network and alert railroads when individual locomotives are not performing optimally, allowing for fast, timely maintenance that minimizes the impact of poor locomotive performance on the environment and network fluidity.
The results are significant: Tier 4 locomotive technology reduces particulate emissions from diesel locomotives by as much as 90% and nitrogen oxide emissions by as much as 80%. As additional locomotives are needed, or older units replaced, Tier 4 Locomotives are being phased into rail fleets nationwide.
Reducing Emissions in the Rail Yard
The freight rail industry’s commitment to sustainability extends beyond locomotives and into rail yards, where trains are sorted and, in some cases, loaded and unloaded.
In the yard, freight railroads use anti-idling technologies to minimize fuel consumption and air pollution. Automatic Engine Start Stop (AESS) units, for instance, turn off a locomotive if it has been idle too long and automatically restart it to prevent freezing if the temperature drops too much. Similarly, Auxiliary Power Units (APU) — small diesel engines — keep the main locomotive engine warm when powered down to prevent freezing in cold weather. These technologies significantly reduce the amount of fuel wasted during idling periods; APUs, for example, can reduce emissions from one locomotive by more than 80 tons of nitrogen oxides, 12 tons of carbon monoxide and three tons of particulate matter, per year.
Zero-emission cranes, rather than traditional diesel cranes, move shipping containers in ports and intermodal facilities across the country, seamlessly transferring goods between ships, trucks and trains. The electric cranes, which reduce ambient noise and pollution, can recharge their own batteries each time they lower a load.
Technologies like these play an important role in decreasing emissions in densely populated urban areas where intermodal rail yards are often located. This commitment to technology is a growing factor in freight rail’s impressive environmental record. Railroads move approximately one-third of all U.S. exports and roughly 40% of long-distance freight volume (measured by ton-miles) in the United States.
Despite the large volume of freight moved, U.S. EPA data show freight railroads only account for 0.5% of total U.S. greenhouse gas emissions and just 1.9% of emissions from transportation-related sources. An 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 13.1 million tons; If 50% of the truck traffic moving at least 750 miles went by rail instead, greenhouse gas emissions would fall by approximately 26.2 million tons.