The latest additions are in bold

Cappasso, Tony, America's Highway: A Journal of Discovery Along US Route 1, Amazon Digital Services, 2012 (for Kindle download only).

DiMento, Joseph F.C., and Ellis, Cliff, Changing Lanes: Visions and Histories of Urban Freeways, The MIT Press, 2013. (The book, according to the book jacket, describes "the evolution of the urban freeway in the United States, from its rural parkway precursors through the construction of the interstate highway system to emerging alternatives for more sustainable urban transportation.")

Yolen-Cohen, Malerie D., Stay on Route 6: Your Guide to All 3,652 Miles of Transcontinental US Route 6, Published by Yolen-Cohen, 2012. (From the back cover: "Beginning on May 20, 2011, I set out from Provincetown, MA, and spent six weeks on the road driving through Massachusetts, Rhode Island, Connecticut, New York, Pennsylvania, Ohio, Indiana, Illinois, Iowa, Nebraska, Colorado, Utah, Nevada and California in order to provide road trippers with the best that US Route 6 has to offer."