What is this?

So does anyone know what the upward facing arrow on the right means? It's a photo from the Tesla navigation screen.

A note from our club member, Dan Rosenblatt, is as follows:

I think it's a slider indicating how close you are to the next transition. That bottom left grey panel shows when there is a transition, usually a turn or highway exit, and in your case an intersection where you should go straight using either of the middle 2 lanes.