I want to begin this review with a disclaimer: every book, or more generally every work of art, has to reviewed in the context in which it was created.
"On the road", by some sources, is "the soul of the Beat movement and literature". Reading reviews, you'll encounter that in it, "Jack Kerouac captured the spirit that was seething underneath 1950s conformity". This is high praise, and for someone in the 1950s reading this book, or at least someone who understands what the 1950s were in the United States, the praise is probably true.
But for me, reading this book in 2009, and being very far, both physically and philosophically, from the Beat movement, it is difficult to find a lot of appeal in "On the road".
Yes, the author did a great job describing the "road bug" many of us, regarding of sex, age and location, are feeling from time to time. The need to roam and travel is an ancient instinct buried deep into our genes. But there is travel, and there is travel. I'm all for road-trips, visiting unusual places and meeting interesting people from different backgrounds. But does it have to be accompanied by a constant state of drugged delirium, be it from marijuana ('tea' as they call it in the book...) or alcohol? Does it have to involve hunger, abysmal states of hygiene and personal health? Is it a must to be involved in stealing, deception and other minor crimes along the way? This is hard for me to believe and to understand.
I've heard that the book used to be a required reading in some American schools. I wonder what it really has to teach. It's based on real characters and is semi-autobiographic. I can bet parts of the book were written in a delirious state induced by some kind of drugs, and I've read that the author has died in a young age from alcoholism, which isn't surprising.
To conclude, this book is probably only suitable for two kinds of readers. The first is people who lead the life described in it. The second is people who have some intimate understanding of the life in the 1950s in the USA, who lived back then or just have a historic interest in the Beat movement. Everyone else should, IMHO, steer clear of it.