Is there no graphic for an up bridge ramp on a downward terrain slope?
No.
Ideally we would seperate the abutment into slope compensation (to flat) and the bridge ramp itself.
That way we could get any combination of terrain slope and bridge ramp:
full height terrain slope, full height ramp slope
full height terrain slope, half height ramp slope
full height terrain slope, no ramp slope
the same for half height terrain slope
no terrain slope would only provide two options: half height bridge ramp and full height bridge ramp.
no terrain slope, no bridge slope is the only special case as in that case there won't be any abutment at all.
However, I guess that's not too easy to implement...