[Edited 20201012 01:10 : Improved edition is now available -
viewtopic.php?p=1236895#p1236895 ]
SUCCESSFULLY
IMPLEMENTED some suggestions - Independence day of Ukraine 20190824 release (
viewtopic.php?f=32&t=85845 ).
There are
descriptions and
files to DOWNLOAD 
(
executable files for MS
Windows and for
Android + set of
modified source-code files). Descriptions (there) include "
How to use?" and about some restrictions.
Contents:

3.
3D-Revolution of (railway-)
stations (these are most powerful new possibilities) :

3.1. (Railway-)
tunnel-platforms (
tunnel-stations) and
bridge-platforms (
bridge-stations).

3.2. (Railway-)
tunnels and
bridges, even if they are not stations,
can be parts of (railway-)
platforms to increase "platform length" parameter of that platforms (
to avoid "platform length penalty" to unloading and loading speed (and time), if platform is shorter than train). This looks like
bridges and tunnels continue that platforms.

2.
More objects under bridges!

2.1.
stations under bridges
2.2.
houses under bridges
2.3.
trees under bridges
2.4.
industries under bridges

1.
Tunnels for ships ("water tunnels").
2-tiles-entrance works quite
realistic ("
continuous").
Be happy.
(This topic is link from "
OpenTTD Development" to the topic in "
OpenTTD Suggestions".)
test test 3.2 for screenshots 2106-02-22, -04-24, 2106-05-22.sav