This game is played by clicking a set of points to thread your transit system, from begining to end, among Oahu's Census blockgroups. You can zoom before setting a point, but for now you can neither erase nor move points and they must be in order.
The display shows blockgroup centroids within 1 km of a station in green, those within 2 km as red, and those further away in black. You can use that to help space stations as you build your system across the map.
The cost per station ($100 million) and per mile of track ($62 million) are rough estimates derived in talking with colleagues in DURP. The calculations here are crude, but they keep the numbers in the right ball park. The point is to have a some number for rought comparison of systems and routes.
Press, hold, drag, and release does zoom (in) to help with station placement. The next press places a station and zooms out to the full map.