“Contempt for my privileged railroad follies may be warranted,” William T. Vollman concedes in the first chapter of “Riding Toward Everywhere” (HarperCollins, 288 pages, $26.95), his account of train-hopping in the contemporary American West. He knows that a fortunate man who does for kicks what a less fortunate man does out of desperation is suspect, and he wants us to know that he knows. But he also knows that riding the railcars as a recreational hobo “gives me pleasure and makes me braver,” and so he’s willing to risk seeming a “dilettante or a hypocrite” if his writing can do for us what his travels have done for him.

It’s a fair bargain, if he can deliver. And even if he can’t, he wants it to be known that “all the same,” his short but scattered account of a handful of illicit train rides “was still written ‘sincerely.'” (The inverted commas are Mr. Vollman’s — no one will fail to see his sincerity.)

He is managing expectations here, as he does throughout the book: Early on, he concedes with admirable forthrightness, and also accuracy, that “My critique of American society is fundamentally incoherent.” Back from many years of exploring the darkest war-torn corners of the earth, Mr. Vollman feels something amiss in his home country. We have, he tells us, grown slavishly conformist and compliant in “plastic America.” We hand over our bags to the inspection of the “security men,” handing over our freedom and dignity in the process.

But he has trouble thinking his grievances through, and even more trouble expressing them cogently. Something is pushing him, in middle age, to endure hardship and exposure, “to skulk like a rat through railyards,” risking illness, injury, violence, or imprisonment on the rails, and all of it is related, in an unspecified way, to his need to break out into some larger, ill-defined freedom.

Sometimes you wonder if the freedom that eludes Vollman isn’t freedom from the compulsion to write. He has no legitimate challenger to the title of world’s most garrulous author, nor for the title of world’s most ambitious author. Nothing but the largest themes will do for him, as his previous work testifies. There was “Rising Up and Rising Down” (2004), the 3,300-page, seven-volume reflection on violence. There is his Seven Dreams series, a projected seven-novel cycle depicting the confrontation between North American Indians and the settlers. In 2005, Vollman won the National Book Award for his 832-page “Europe Central,” a series of “parables about famous, infamous and anonymous European moral actors at moments of decision.” Taken as a whole, his massive and still burgeoning body of work seems the triumphant product of the world’s most heroically self-actualized sophomore.

“Riding Toward Everywhere” is a minnow swimming alongside these whales. But Mr. Vollman addresses his railcar “follies” in the same way he does everything else in the rest of his work. He careens from hyperventilating flights of lyricism to rubbing the reader’s face in the world’s filth, from earnest rumination on the world’s moral condition to sudden gestures of renunciation of all meaning and purpose, especially his own. This honesty ceases to be refreshing once you’ve seen it repeated a few dozen times.

There is an organized group riding the rails, he reports, that kills for sport and tattoos their kills on their bodies. Nonetheless, to be out among the rails, not just theoretically but practically within the reach of such people, remains preferable to “sitting clean, comfortable and legal on a passenger train whose windows are invariably small and dusty.” There’s the exhilaration of breaking the rules, and the sensual excitement of it all, which he evokes beautifully, about which more anon. But then questions still linger.

“Isn’t going anywhere the same as going nowhere?” he asks. “Isn’t running away from everything the same as running toward everything? In which case, isn’t fear the same as happiness? Would I be riding the freight trains if I wasn’t trying to escape from something?” Anyone can think such confused, meaninglessly portentous thoughts; Mr. Vollman writes them down, and then publishes them. Moreover, he means them, though not in the sense that you mean a question when you want it to be answered.

“Do I love shadows because I fear the third dimension? Am I a writer and a printmaker in an effort to control my perception of the world by constricting it to my level?” Finally, he wonders, “aren’t all these questions, which rush through my mind and depart unanswered, nothing but shadow-shows themselves?” He has a gift for remaining two steps behind the reader when it comes to staying a step ahead of him.

But that’s Mr. Vollman for you. He is fearless in the greater and lesser senses of that word: Unafraid to venture into war zones, consort with junkies, prostitutes, the homeless, and the mujahideen, he risks his life for a fugitive glimpse of other people’s hidden sorrow and pain. Often he outraces his lesser tendencies. Sometimes he lives up to his reputation as the outstanding poète maudit and gramophone of the age.

But he also, alas, has the courage to be interminable. He does not flinch from writing dreadful sentences (a man who stops talking joins “the army of the silent”). He has the wherewithal to be a stilted parody of Walt Whitman (“I love cities as much as solitude, prostitutes as much as trees”), and the cojones to wallow in pseudo-profundity (“Where am I? What if I am not here because I am not myself?”).

He also portrays the handful of lost souls he encounters on the rails with beautiful simplicity and kindness. “I remember that half of his snaggly teeth were missing, I remember that one eye was open wider than the other, and I recollect very well the two pale lumps on his left eyebrow, but his smile was so gentle and loving and good, and he was so shyly patient the way he stood there with branches poking into his wrinkled neck; he was as lonely and eager to play as an abandoned child.”

It’s not enough. Without the exoticism, extremity, or world historical ballast of his other works, Mr. Vollman can’t keep the reader engaged. Early on, he confesses to the dearth of his ideas. “I apologize if I make this point too often. I have few points to make.” Closer to the end, he reflects on how little he has said in so many words. A good magazine-sized idea makes for an unwieldy book, even at 288 pages.

For all that you come away from it with, liking Mr. Vollman and admiring things about him, “Riding Toward Everywhere,” if you manage to make it all the way through, is a pleasure to put down.

I had expected my travels to be picaresque, teeming with wise, bizarre or menacing outlaw characters. In fact my various odysseys were haunted by absence, with only here and there a few lost voices — singing about the way things used to be back then, as if they were crickets who had inexplicably outlived the summer.

Mr. Yang is a writer in Jersey City.