That obviously varies drastically by city. In this case, DC and Tokyo have airports close to downtown and connected by subway. And these airports could connect you to the entire world of course, rather than within ~500 miles (reasonably).

And the only reason train stations are downtown is due to historical reasons. If you had to make a 35 track train station today in your average American city, it would very likely not be downtown. Even in China these train stations are often on the outside loop of the city.

> If you had to make a 35 track train station today in your average American city, it would very likely not be downtown.

In Seattle, the trains used to run through the city. The corridors are still there, but the new light rail system avoids using them, making it far, far more expensive.

They recently dug a new transit tunnel under the city. The best use for the old tunnel they could think of was to fill it with the rubble dug out of the new one.

The expensive tunnel boring machine was sold for scrap.

I don't understand the thought processes involved in these decisions.

Plus you save a lot of time not having to go to and through the airport.

To compare travel times you can easily consider a 2-hour advantage to the train.