Residents here can rent a sturdy bicycle from hundreds of public stations and pedal to their destinations, an inexpensive, healthy and low-carbon alternative to hopping in a car or bus.

But this latest French utopia has met a prosaic reality: Many of the specially designed bikes, which cost $3,500 each, are showing up on black markets in Eastern Europe and northern Africa. Many others are being spirited away for urban joy rides, then ditched by roadsides, their wheels bent and tires stripped.

Sad. But $3,500 each?