Not intended and no bug I would say. For early games (pre 1920) you still get only the lower crossing as the other one is not available. But I am open for discussion.
The 110.0 effect could be recovered defining two different crossings with same picture but different max-speed:
obj=crossing
name=rail-road-crossing-slow-road
copyright=Hajo/prissi
#no sound
waytype[0]=road
waytype[1]=track
speed[0]=30
speed[1]=400
intro_year=1810
[...]
---
obj=crossing
name=rail-road-crossing-slow-rail
copyright=Hajo/prissi
#no sound
waytype[0]=road
waytype[1]=track
speed[0]=250
speed[1]=60
intro_year=1810
[...]