Hitchhiking means to travel by getting a ride in someone else's vehicle, usually by sticking out your thumb on the side of the road and hoping they will pick you up. Full definition
The 2011 east Japan tsunami swept huge amounts of wreckage out to sea — and Japanese species hitchhiked across the Pacific on the debris. (scientificamerican.com)
Lost pets can travel some distance (either on their own, by hitchhiking on a vehicle, or by being rescued and then lost again in a new location) and may be farther away from home than you think. (bestfriends.org)
While on journey hitchhiking from east coast to LA. (mediamikes.com)