A lot of cost savings come from just producing things in volume. The Chinese may be way over-building the infrastructure, but they're building so much that the

A lot of cost savings come from just producing things in volume. The Chinese may be way over-building the infrastructure, but they're building so much that their industry is quite good at it. Contrast that with the US where these infrastructure projects are relatively uncommon and the industries that support them are small and high cost. If you have to keep an industry alive on only a handful of projects each decade then those projects are necessarily going to be expensive, probably outrageously so.