Simutrans r11049
pak64.nippon 0.6.2
With pak64.nippon, no bridges outside of cities are built during map generation.
Some are being built within cities.
I'm not sure whether it's an error in the pakset or the error lies with Simutrans.
This applies to flat ground above water.
no_build_bridge.png
In pak128.japan, the same behavior is occured in r11266.
I can't build halt height bridge to river and lake, but sea is OK.
I think when tile height of pakset is half height, this problem comes to light.
not_build_bridge.png
Unless a river is non-navigatable (top speed 0), it is counted as a way. So it has a height restriction. The sea has tides, so we assume we can always pass ...
The terraforming to allow double height bridges is too complicated for the simple terraforming way finder. Thare is not much which can be done about this, apart from setting the height to single height for passing.