Planes, Trains, Cars, & Buses – What’s the most fuel efficient way to travel?

The quick answer (for the US) is buses, but as you already know there’s more to it.

Here’s a quick overview:

  • For domestic travel buses are by far the most fuel efficient (in the US).
  • For long distance travel planes can actually be the most efficient.
  • The key measurement that impacts efficiency is miles per gallon per person. Variables that impact this include:
    • How much fuel is needed to move the vehicle
    • How many people are being transported
    • How far you are traveling
  • If you’re in a hurry: Action items for being conscious about fuel efficiency while traveling are included at the end of this post.

The full explanation of fuel efficiency by vehicle type:

To understand the fuel efficiency of planes vs buses vs trains vs cars, we need to look at two variables:

  • How much fuel does it take to move the vehicle
  • How many people can the vehicle carry

Cars (especially modern fuel efficient cars) burn less fuel than buses, trains, and planes, but they also carry a lot less people. Planes burn a tremendous amount of fuel (especially in take off) but they can also transport quite a few people. Trains and buses also take a lot of energy to move because of their size, but can move many people at once.

Public transportation tends to be more eco friendly, but as always this isn’t a straight forward comparison. To determine which mode of transport is the most fuel efficient you’ll need to consider a few things.

How far are you traveling?

It turns out that a big distinguishing factor to determining the greenest way to travel is distance. Although planes burn fuel at an aggressive rate, their ability to carry a large number of people can actually make them a more fuel-efficient mode of transportation over long distances.

A generalized estimate for a Boeing 747 (from How Stuff Works) says that this plane burns about 5 gallons of fuel per mile, but with a capacity to transport over 500 people the miles per gallon per person is more like 100. Smaller planes aren’t as efficient and due to the large fuel consumption of take off, shorter distances bring that average down.

What’s the deal with the fuel efficiency of trains?

In the fuel efficiency information provided below you’ll see that trains are unexpectedly low, but this data can be a bit misleading because it’s from research that only studied trains in the US. There are two things to note:

  1. Americans don’t utilize trains as a mode of transportation very much in comparison with European and Asian countries. This brings fuel efficiency down because there are less people being transported per train moving.
  2. Trains have varying fuel efficiencies themselves. They are powered by either a normal combustion engine using diesel fuel or an electric motor. The efficiency of electric trains is highly variable because of the source of electricity. Electricity from a coal fired power plant will be much less efficient then renewable resources such as hydroelectric, wind, or solar.

The information provided below is from a study of Amtrak trains in the US, most of which are diesel powered, which brings their fuel efficiency down considerably.

The data

The International Council on Clean Transportation (ICCT) is a non-profit that seeks to provide research and analysis to environmental regulators. They have some great information about fuel efficiency on their site and I’ve summarized a bit of it here to help you get the big picture for how different modes of transportation stack up against each other. (More info on the ICCT in the footnotes)

This graph shows an estimate of miles per gallon per passenger. It’s important to note that this data is a comparison for domestic travel, specifically intercity travel within the US. Despite the limited scope it serves as a good overall approximation.

Trains in countries like Japan are predominantly electric and transport a much larger number of people per cabin than trains in the US. While it’s difficult to broadly compare trains between regions it’s safe to say that trains in European and Asian countries are far more fuel efficient than those in the US, making them a leading option for travel.

In most cases outside of the US, trains are probably at least as efficient as buses and are much more efficient than cars and planes.

Your general guide to traveling:

  • Planes are okay for long distance travel but inefficient for domestic travel.
  • In the US: Buses are best for domestic travel.
  • In the US: Cars are generally more efficient than trains when there are 2 or more people traveling.
  • Outside of the US: Trains are likely the most efficient mode of travel, but varies based on distance and train type. Buses are the next best thing and are potentially better in some instances.


About the ICCT – their Mission statement

The International Council on Clean Transportation is an independent nonprofit organization founded to provide first-rate, unbiased research and technical and scientific analysis to environmental regulators. Our mission is to improve the environmental performance and energy efficiency of road, marine, and air transportation, in order to benefit public health and mitigate climate change.

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  1. The conclusions are too broad, using Amtrak as representative of all rail transit is a fatal flaw.
    Rail transit in the form of streetcars or trams is in most cases more efficient than buses under the same conditions, same capacity over similar distances.

    1. Thanks for your input Barry. You have a good point. Streetcars or trams are not addressed in this post, but likely are more efficient. There is a fair amount of variation based on type and fuel source which adds another variable.

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