Because Austria uses those 2 voltages. The standard is 15kV in Germany. Germany also use 15kV and 25kV. 25kV is standard in Austria.
This is wrong. Austria uses 15kV almost everywhere. There are only two short sections south of Vienna that use 25 kV. Yes it does. You need to use the one that corresponds to the actual voltage on the wire you're driving beneath. In all Austrian routes currently in the game that means you need to use the 15kV setting.
Even if I have it set to Austria settings should have reset the breaker when I go through change over zone just outside of wiener nesault