While I was in Glasgow, I travelled on their subway system, which consists of a simple line looping round the city.
When you catch the trains, you can take the grey line which is labelled 'Inner' or the orange line which is labelled 'Outer'.
Now, while it is technically correct that the trains along the grey line go along a track that is always on the inside of the loop compared to the trains along the orange line, that reflects an engineering point of view which is not particularly helpful for users. What customers need to know is whether the trains are going clockwise or anticlockwise, and that is far from obvious. (There is a little arrow there, showing the orange line going clockwise, but is is far from obvious, and the signs in the stations don't show it.)
I guess locals get used to it, and Inner and Outer make perfect sense once one gets used to them; but it doesn't seem very user-friendly for a first-time visitor to Glasgow.