I think there'd be traffic...
I agree with Glenn Reynolds about 95% of the time. This falls in the other 5%:
AN UNDERGROUND TUNNEL BETWEEN RUSSIA AND ALASKA? Now there's an engineering project for you. Hard to believe there'd be sufficient traffic to justify it, but . . . .
Perhaps Glenn's being sarcastic and I'm not picking up on it, but I would imagine that a solitary land gateway - offering road, rail, and pipeline connections - between four continents could find some traffic.
I wouldn't start calling this "Viktor Razbegin's Folly."
UPDATE (from Phil):
More on the Hemespheric Highway over on L2si. If nothing else, this new tunnel will give us a distinct advantage over one of Google Maps' most (in)famous sets of driving directions.
UPDATE (from Stephen):
Make that five continents. It would be possible to drive to Africa too.
Glenn Reynolds responds:
Problem is, it's a long way from anywhere. It's nice to connect Siberia and Alaska -- making it, as Phil Bowermaster notes, possible to drive from Paris, Texas to Paris, France. But Alaska itself is a long way from anywhere, and there aren't even rail and road connections to the Bering Strait areas where the tunnel would go.
It's certainly no Sunday afternoon drive. But the value of connecting the new and old worlds would be very important for business. That industrial traffic would be so important that I would speculate a "field of dreams" effect on the rest of the needed infrastructure - build the tunnel, and it will come.