There is actually a proposal to build a railroad tunnel across the Bering strait, to connect the Eurasian (Russian) rail grid with the U.S./Canadian rail grid, which the Chinese are very much interested in. In fact, if you look at the connection from Beijing through the Bering strait to Chicago, it turns out to be the shortest possible route. Experts estimate that approx. 3% of the world's goods transport could be routed through that tunnel, making it extremely economical, even if you include the thousands of miles of rail that would have to be build to connect the tunnel on the Alaskan side to the US/Canadian rail system, and to the Transsib rail line on the Russian side.