As the motorbike taxi I'm aboard zigzags through the traffic in Da Nang, Vietnam's fourth-largest city, a bus pulls out of nowhere, causing my driver to brake, swerve and slam us into a sidewalk stack of bamboo cages packed with soft plump ducklings.

It's as gentle an impact as anyone involved in a crash could wish for, but my driver seems shaken by our shenanigans as he points at the street from where the bus suddenly materialized. "That's a new road. It wasn't there last week," he exclaims. Then, picking feathers from his Honda's mudguard, he seems to reconsider. "Come to think of it, it wasn't even there this morning."

Given the phenomenal pace of growth in Da Nang, the taxi driver's explanation is entirely plausible. Scaffolded tower blocks rake the skyline, shiny malls crowd busy intersections and, along the coast, new hotels compete for views over the South China Sea. Much of this growth has been fueled by Japanese investment: from the sportswear factories on its outskirts to the Japanese co-designed Hai Van tunnel — at 6 km, the longest in Southeast Asia.