I'm also close enough to a railway line to see the trains. There are two lines near us - a fast line (that I can see) and a slow line on the other side of the estate. The map showed a train moving (quickly) on the slow line, at just about the time I saw it fly past out my window. So it isn't even accurate as to which line the train is on.

Possibly useful as a funky station arrival board, but overlaying that data on an actual map is a bit misleading.