It is easy to see why a book about traffic would become a bestseller. Congestion on the roads robs people of time. A book that promises to explain it has the same potential appeal as one that tells people how the Internal Revenue Service robs them of money or cholesterol robs them of longevity. But it is for different reasons that Traffic, by the science journalist Tom Vanderbilt, has become the big succès d’estime of the US summer publishing season. Critics have treated it almost as a work of philosophy. The book is intensely researched and quite readable, albeit in that bantering, overly personal, hey-what-the-heck style of much US pop economics writing. Traffic is not just about slow commutes. It is about the way things flow through networks more generally, and the hazards and opportunities that result. For Mr Vanderbilt, the highway is “a living laboratory of human interaction, a place thriving with subtle displays of implied power”.

Automobile traffic is one of the most studied phenomena in advanced societies. Managing it is a main function of government. Private institutions study traffic, too – Disney World must shuttle visitors efficiently between its attractions and Wal-Mart needs to estimate its parking needs for each new store. The result is a mountain of university research, government policy documents, consultant reports and industry journalism. Mr Vanderbilt has mastered all of it. Arresting facts appear on every page: three-car households outnumber one-car households in the US, iPods are more dangerous to adjust while driving than car radios and cyclists who use proper hand signals cause more accidents than those who do not signal at all.