> Following several decades of planning and construction, the tunnel opened on 13 March 1988.

> The construction cost of the tunnel itself was 538.4 billion yen at the planning stage, but it actually cost 745.5 billion yen. The construction cost of the strait line, including the attachment line, was 689 billion yen at the planning stage, but ended up costing 900 billion yen. During the construction, 34 workers were killed in the Seikan Tunnel, mostly in transportation accidents

> In addition, the tunnel faced criticism for its high maintenance costs, the need to pump a large amount of spring water even after completion, and that the large investment to build it is regarded as a sunk cost, and it is said that it is more economical to abandon it. It was ridiculed variously as "Showa's Three Idiots Assessment", "useless long things", and "quagmire tunnel".

We're complaining about CAHSR being decades in the making and billions over budget, but this does not seem to be unique to CAHSR. At least nobody's died during construction yet.

It's good evidence that all civil engineering projects are failures right up until they're done and everybody uses them, and then they just become critical infrastructure.