Here's the quick version of "On the Road:"

"Where are we going, man?"

"I don't know, but we gotta go."

This exchange between Sal Paradise (Jack Kerouac) and Dean Moriarty (Neal Cassady) occurs after both have put many miles on their young, aimless lives and they still thirst for travel.

There's nothing else they care about -- women, children, careers, they're all transitory or unimportant. It's the freedom and camaraderie of the highway, bar and flophouse that matter.

Read in the America of 2007, 50 years after it was first published, Kerouac's novel is still impressive as a sustained jazz- and Benzedrine-powered piece of pure writing. Reading some passages is like grabbing an electric wire and feeling the jolts of energy passing from his fingers to the typewriter keys.

His account of a trip on the Pan American Highway to Mexico City can stand alongside some of the best writing in 20th-century fiction.

"On the Road" is mostly style; substance isn't Kerouac's concern. It's the moment that counts. Forget that Moriarty is a thief, liar and heel to women. Or is that Sal?

Actually it's both, and it's hard at times to know if they're really two people or an amalgam. Occasionally Sal has "plans" for his life, mostly ways he can leech off his family and friends and how he can use his GI Bill benefits to get drunk.

Dean briefly entertains a notion to write, but fathering two families and parking cars is as far as he gets. He can give off some Zen riffs now and then, usually at 80 miles per hour, while Sal prefers to "read the American landscape" through the window.

What's often overlooked in commentaries on this book is the wretched poverty of its heroes and their surroundings. They're always broke, as are their many road companions who are offered rides in hopes of getting their money.

Friends live in hovels, eating is hit or miss, their clothes are second-hand. Hired to drive a wealthy man's Cadillac to Chicago, Dean drops it off as a total wreck.

This lack of concern about material things no longer seems "romantic," though, but a picture of underclass America in the uncertain days following World War II.

As his friend William Burroughs once said, "On the Road" sold a lot of Levis, but others also bought Kerouac's visions of finding the spiritual world, if not God, in the rolling of wheels through the American landscape.

Passing today's scenery of strip malls, car lots and cell phone towers, his vision seems naively romantic, a glimpse of a lost world closer to the era of dinosaurs.

As a novel, "On the Road" is in danger of becoming a piece of archaeology that, unlike the accepted "classics" of American literature, requires the specific times and places of its story to be fully realized and understood.