McCarthy, of course, is notoriously reticent about discussing his own works, so he has not made it clear exactly why he chose not to name the characters i(at least not saying their given names) in The Road. It seems clear, though, that his decision not to use names beyond "Papa," "the boy," and others is connected to the mood he creates in the book. The man and his son are travelling through a world in which almost every recognizable aspect of humanity has been destroyed except for human bodies themselves. So physically describing the people is a way to underscore the point: many of the characters in the book are not human in the sense that we understand humanity. Few things are more associated with human identity than given names, so McCarthy's decision not to use them is not only in keeping with his spare prose, but makes sense given the overall themes of the novel.