Two of my recent additions to my library are "The Open Road" by David Campany (Aperture 2014) and "Both Sides of Sunset: Photographing Los Angeles" by Metropolis Books (2015).
"The Open Road" is a beautifully printed book featuring 19 well known photographers like Lee Friedlander, Alec Soth, Robert Frank, Garry Winogrand, and Inge Morath and images from their travels. Another good documentation, this time of America. I especially liked the maps in the back of the book showing the locations where the images were taken. I think it was a perfect fit with the road trip theme, made the document complete. Again I highly recommend this book for anyone who enjoys documentary photography.