Allows train tracks to be built over tunnel entrances.
2.0.1 alpha 69 or later
Configuration file: enhancetunnels on|off
Command line: N/A
With this switch on, train tracks can be built over tunnel entrances creating so called "tunnel bridges" (90° angle from the tunnel entrance).
Graphical glitches that are not expected to be fixed until the new graphical subsystem is implemented sometime after the next stable release.
This feature was contributed by Oskar Eisemuth.