This element of the UI could do with a bit of the improvement, since it always refers to the "front" of the locomotive, even when running in reverse, which can be a bit confusing. This is especially a problem for locos like the Class 20 which are often run in what the game considers backwards.
I already opened a thread about that, and official response was given! To me it seems confusing as well, but it is what it is!
Oh? What was the response? I took a screenshot that I think perfectly demonstrates the issue in which I am descending a slope but the UI seems to indicate an up slope: