This was quite an excellent little book. The text I read is buried in one of those thick American Library compilations, this one is London's "Novels and Social Writing." This was published in 1927 and accounts for a time probably about ten years earlier. Maybe even earlier, I don't know - there is no context given in these books (though I have not read the Introduction because of the inevitable prejudicing that occurs, and to avoid any spoilers).
First, the road that London is writing about is the railroad. I have no evidence to suggest it except for the books themselves, but I suspect that Kerouac named his 1957 classic after London's.
The first few chapters discuss how to beg for food. Tons of good hobo slang here. And he tells about how he can make up stories on the fly, making judgments about the people at the door in order to tailor his story for maximum effect. Later on, he regrets telling such whoppers because he may have been wasted his fiction.
The next section gets down to the railroad. Very interesting chapters on how to avoid getting thrown off a freight, where to sit, more importantly, where not to sit, and how to get on the good side of the engineer (offering to shovel coal for him). Also a lot of techniques about how to catch a freight, too.
And then, a section on how he got into tramping in the first place. When he began his life on the streets he was a thief. Then he met some kids who rode the rails and they taught him how to beg. He found the begging to be more noble than stealing - the begging was relying on your wits, charisma, and ability to spin a yarn.
Overall it was a pretty cool book. Lot of adventure running scams and avoiding scams, lots of lingo, and techniques about the tramp life. Seems like he saw a lot of the country, and saw a lot of the country that not many people ever even think about - the tramps, hoboes, and various outsiders who live away from the mainstream's conciousness.