OpenBVE v1.7.2.2

Significant Changes:

• New: Add HornBlow routefile command, to tell the AI driver to sound a horn.
• Change: The AI driver has a small random delay before opening the train doors when the train stops.
• Change: Update zh-HK translation- Thanks!
• Change: Improvements to the Wavefront OBJ parsers when handling SketchUp generated files.
• Fix: The StopTime variable for an API station could return invalid values.
• Fix: The door direction for a station could be wrong. (Introduced in 1.7.2.0)
• Fix: Detect and handle where the settings file is set to be stored in the program directory, but we have no write access.