From Darach: Hitching (aka hitch-hiking) is a great eco-friendly option, with the added bonus of making connections and having an exchange / experience / conversation with, most likely,  local people. I know hitching doesn’t suit everyone and is not appropriate for everyone, and it does require a certain level of dedication, but for some people it is very suitable and a bit of adventure at the same time. There are websites / forums / apps that are useful for hitchhikers, such as hitchwiki.org  (community site of map with locations and rating hitching spots).