the union of concerned scientists have a 2008 report (pdf) that details the greenest way to travel, depending on whether you’re flying solo, traveling as a couple or in a small group. even with technological advancements, their findings hold true, according to the 2015 u.s. transportation energy data energy book, which includes data up to year 2013.

so should you fly, drive or ride?

the answer, perhaps surprisingly, is to hop on a bus — specifically a city-to-city bus. the american bus association’s motorcoach census for 2013 found that though the average mileage for a bus is just 6.1 mpg, an industry average of 39.3 passengers per trip resulted in 222.7 mpg per passenger. this is the best option for the environment — regardless of distance and whether you’re traveling alone or not.

if you’re traveling between 100 and 500 miles, the second best option is to hop on a train, with 56.18 mpg per passenger. the third best choice (for a single person) is to fly economy. the average mileage for a plane per gallon per seat is between 50 and 64 miles depending on distance traveled and whether it is a non-stop flight. if you can, try to find a plane that seats all economy as these have the lowest carbon footprint.

cars can be quite environmentally friendly as long as the car is filled to capacity and fuel efficient. if you are comfortable traveling with strangers, then a service like rideshare may be the one for you.

if you still feel like you need to drive yourself home for the holidays, here are a few practical tips from earth share:

1. keep your speed around 50 mph: speeds far above or below this number result in fewer miles per gallon.

2. don’t travel during peak hours: traffic is bound to be problematic — for your stress level and for your gas tank. being stuck in traffic is one of the best ways to burn through gas at a quicker rate.

3. pack light: traveling with less weight in any vehicle (plane, train, bus, car, etc. …) will conserve energy because the machine will not have to work as hard to lug all your stuff at high speeds. take only the essentials and you will find that your travels will be more efficient all around.

(image at top: plane by urvile86; bus and train by adam e. moreira; highway by minesweeper. / creative commons)