Ever wonder what it looks like when they dig tunnels for expressways?

I lost count of the number of times my wife and I have discussed Japanese tunnel engineering while on road trips.  Look, we’ve driven through the 10 kilometer long Joetsu tunnel umpteen times now, and it never gets less impressive.

We’ve often wondered how they make the tunnels, and during our most recent road trip, we got to see it first hand.

We were snaking through the mountains of Yamaguchi prefecture, remarking to ourselves, “Man, this would be much easier if there were just a tunnel,” when we saw this:

They had built the road right up to the edge of the mountain, cleared the foliage, and poured concrete down the face of the cleared space.  From there, they marked the area necessary to remove from the tunnel, and put in guides for the tunnel boring machine.  

All in all, a pretty neat sight to stop for along our windy mountain drive.