Stephen Smith on why HS2 is such a cause of national hand-wringing.

'We get railways, we do railways - ever since Stephenson's Rocket in the nineteenth century. We gave railways to the world', writes Stephen.

He argues that there would never have been the same sense of dismay if we were talking about a road or a runway.

Producer: Adele Armstrong

Note to clarify: The Thames Tunnel used an innovative design, but not cut-and-cover.