Walk the Line

This is the Singapore MRT North-South Line. It is a line, it has two ends, simple.

This is the Berlin U-Bahn U1 Line. Again, two ends, from one point to another.

Paris Metro this time. Number 2 Line (don't snigger). As I'm sure you've noticed, it is called a Line and is, more or less, a line.

Now we have the London Tube District Line.

This is not a line. This is a god damned mess. Get your act together London.