Weaving its way through a maze of broccoli-coloured islands in waters where Orca whales can be spotted during the summer months, the journey crosses the invisible frontier between the urban frenzy of Seattle and the soporific rhythms of the Puget Sound, the inland sea in which the San Juan Islands are located .

BBC: Cycling the San Juan Islands

For most drivers, the time-savings, about a minute on a 60-mile journey, will be so small as to be invisible.

ECONOMIST: Transport strategy