Wanderu recently published the results from its latest study, showing that buses are even more eco-friendly than trains (by up to 50%).

Takeaways from Wanderu's Study

Key takeaways from the study include:

• Intercity buses are the most sustainable mode of transportation in the U.S.

• Intercity buses are 550% more fuel efficient than cars on a per-passenger basis.

• Taking the bus instead of flying can decrease your carbon footprint by up to 77.5%.

• Trains produce less CO2 emissions per passenger than planes, and the average Amtrak train can carry more passengers than the average domestic jet plane.

The study also checked out the average carbon dioxide emissions for each of these travel modes. The Congressional Budget Office has reported that transportation is the largest source of carbon dioxide emissions in the U.S., and 83% of emissions in the transportation sector come from cars and trucks. 

Based on the study's fuel efficiency and carbon dioxide emission data, the most sustainable mode of traveling in the U.S. is via intercity bus, followed by trains. Intercity buses use 280.1 passenger miles/gallon, while trains use 79.8 passenger miles/gallon.

Average CO2 Emissions

Intercity buses carry 0.15 lbs/passenger miles, while trains carry 0.30 lbs/passenger mile.

Driving releases almost half a pound of carbon dioxide for every passenger, every mile. This means even a 20-mile drive can release 10 pounds of carbon dioxide into the atmosphere. It would take one tree about six months to recapture the carbon dioxide released on this short drive.

Traveling by bus rather than flying could decrease your carbon footprint by up to 77.5%.

Average Maximum Capacity of Vehicles

An average intercity bus can fit up to 55 people on board, while the average personal car can carry up to five passengers at a time.

According to the Bureau of Transportation Statistics, the average car carries only between one and two passengers. Therefore, one bus can take as many as 55 cars off the road.

While trains might be a little less efficient than buses, their higher capacity makes the overall footprint of each train much lower than an airplane.

The average Amtrak train can carry more people than the average domestic jet plane, compounding the positive effects of a lower per-passenger carbon footprint.