If you want the perfect pillow for travel then look at this Arc4life Travel Pillow.
This pillow is made from memory foam and is like a straight tube that you can fold in all kinds of ways to make it into the pillow for your needs.
And this pillow has a removable and machine washable cover. The travel pillow is 25.5 x 4 inches and has a little strap on the ends to connect both pieces together to make it in the typical u shape travel pillow.
This maybe the pillow you can use in trains, plains, cars and the hotel room as it is good for you neck as a main pillow too.