Lee Myung-bak

South Korea's infrastructure boondoggle a boon for cyclists

In a country where bikes are either a poor man's transportation or a weekend workout for spandex-clad racers, the longest and most highly engineered network of car-free paths in the world is being built through dense evergreen forests, down wildflower-lined river valleys and over steep mountain crests.

"If you like speeding fast you will need to train, but if you want to go slow, anyone can enjoy riding our paths," said Moon-wan Sup, a South Korean high school teacher who has ridden the entire 2,700-kilometer (1,677-mile) of trails completed to date.

Construction of the multimillion-dollar bike network was met with widespread disdain a decade ago as an expensive...