Rail travel is cleaner than driving or flying, but will Americans buy in?

Transportation represents a large portion – about 29 percent – of U.S. emissions, and the share has been rising in recent years. Rail proponents often argue that investment in trains and public transportation is a key part of making transportation cleaner, and indeed, the Green New Deal calls for greatly expanding high-speed rail.

I’m a scholar of rail, and it’s clear to me that the quickest way to decrease greenhouse gases from transportation is to travel by train and move goods by rail instead of on the road or by air.

To explain why, it’s worth comparing rail to other modes of transportation on energy consumption and emissions, and to look at some of the developments that can make rail more widely used in the U.S. and less reliant on fossil fuels.

Energy and emissions profiles

Transportation by rail is a major part of the transportation system in most countries, including in the U.S., which has the longest freight railway system in the world with approximately 140,000 miles. Rail passenger services are essential in many areas, primarily in population centers such as New York and Chicago, and intercity rail has a significant market share in some corridors, such as the Northeast. Rail also offers long-distance routes connecting many smaller communities with each other and the large metropolitan areas in the country.

Data show that rail has a significantly lower energy footprint than trucks and passenger cars. Rail transport, with hard steel wheels on steel rail, has lower resistance to motion than road transportation. And the convoy formation of individual rail cars into trains also adds to its better energy and environmental performance.

A common measure for transportation capacity is ton-miles for freight and passenger-miles for passengers to indicate that a ton of freight is moved for one mile and for passenger systems that a passenger is moved for one mile.

Freight rail accounts for about one-third of the ton-miles and consumes only about 2 percent of the transportation energy in the U.S. The higher efficiency can be illustrated this way: On average, freight railroads move a ton of cargo for around 479 miles on a gallon of fuel, which is about 11 times more energy-efficient than trucks on a ton-mile basis.

Passenger rail is around three times more efficient than a car on a passenger-mile basis at current occupancy levels. The lower energy consumption leads to lower greenhouse emissions.

How US and European rail differ

Often there is the perception that the U.S. lags behind other countries when it comes to rail, but in many cases that is not true. The country has, arguably, the best freight rail system in the world, which is owned, operated and financed by private companies. Passenger service in specific corridors is comparable with the European counterparts: for example, in the Northeast. On long-distance routes and in less densely populated areas, however, there are often empty seats on Amtrak trains.

The U.S. freight train system is more developed than passenger rail, which is the opposite of Europe. Jeffy zilla, CC BY
The primary difference between Europe and North America could be summarized like this: In America there is a freight rail system with some passenger, while in Europe there is a passenger rail system with some freight – the emphasis is different.

A further difference is that the rail network is private in the U.S. and operated to yield a profit, while in most other countries the rail infrastructure is owned by the government (similar to the freeway system in the U.S.) and heavily subsidized.