The novel The Road begins in medias res, which is a Latin phrase for "in the middle of things." The reader is thrown into the story much like the characters who fight for survival. A traditional exposition and rising action are not the hallmarks of horror or science fiction, which are organized around suspense and wonder. McCarthy places the reader in the middle of the action, walking on the road with the man and boy, staring at the ghastly images along the way. The climax has already happened (the apocalypse), and now we journey where none have gone before, as if into hell.
McCormac creates suspense by giving the man a gun with two bullets (there's two of them), and intermingling the horrific flashbacks of the mother's suicide along the way. Not only are there marauders and cannibals that the man must fight, but we wonder if he will end his son's life the way his wife wanted him to. In this way, the turn of each page could be a potential climax or resolution.
McCormac's novel is episodic in structure. It is series of episodes, vignettes, with no chapter titles or markers, only double-space breaks, so that the novel is organized very much like an unmarked journey, much like The Odyssey, Huckleberry Finn, and Catcher in the Rye. All these stories involved lonely characters who journey to unknown destinations, who have been alienated by the world around them, who battle antagonists and nature along the way.
The ending has elements of a Deux ex Machina, but if you go back and look for clues, you will find out that the man with the shotgun (and family) have indeed been following them for some time. And still, McCarthy leaves the novel open-ended, as the boy's future still looks bleak.
The structure of The Road is very unique, and serves to enhance the theme of timelessness, hopelessness, and gray monotony that is the characters' lives. Imagine living in a world where one day is exactly the same as the rest, where there is no variance in the landscape, where there is no hope, no beginning, and no end in sight. That is the world that the father and the son live in. The novel itself reflects that feeling in its unusual structure. Because it doesn't have a typical plot chart, the reader is left feeling much the same way as the characters are--weary, wondering where the end is, and what is going to happen. McCormac makes it possible for the reader to go through what the characters are going through in that way.
Even though there is not a typical beginning, middle and end, through the use of flashbacks, McCarthy is able to provide key information that lets us know how everything happened. By the end of the novel, we know how it all began, how the mother left the picture, and how they have been struggling. We get the entire picture anyway, but not telling it in a classical condition puts us in the shoes of the father himself. All he is left with is the dragging present time, with only fleeting memories to comfort himself. We can travel that difficult journey with him in the way that the novel is structured. I hope that helped; good luck!
I believe that the author chose the particular structure for the story to demonstrate the desolation and feeling of desperate unending and outcome of the trip that the boy and the man are undertaking. Theirs is not a start and finish journey but rather a sense of loss and desperate isolation as they move in search of life that could be different and better than their current existence.
The boy came at a time when there really was an ending of a social order and lifestyle not a beginning. The man and the boy have lived through the hell of what life had become on earth. The boy had never experienced things any different but the man remembers. The reader is actually put into the journey as the boy was born into it. Therefore, there would have been no beginning of the book.
The journey is on going. Even after the father’s death the reader has no idea nor does the boy if things will be better or not. The journey down the road in the desolate and burnt world continues. There has been no sign of growth in plants or real hope through the book to give us hope even in the last pages.