Comment by walrus01

Advancements in boring technology for small stuff (1.5 meter diameter utility tunnels) would also be a game changer in major urban areas. If you need to do cut and cover trenching to install vaults/manholes and duct for underground fiber in a major city nowadays, a several km distance project can run anywhere from $400 to $1000 per meter or more. Traffic closures, street closures, flagging, shoring of excavations, moving big construction equipment around on flatbed trailer in urban cores, etc.

To the extent that at $800/meter, a 4 km fiber path could cost $3.2m.

A bored small diameter service tunnel sized lined with concrete sections (basically a mini version of what the Bertha TBM in Seattle has just finished boring), sized to accommodate small electric carts that could be shared by multiple cables stuck to walls would be a game changer.