In response to the original post, here is my reply to the same question in another
thread. Nothing that I have seen in Trainz Plus or TRS22PE has altered my understanding (described below) of how this works.
Drive To
Instructs the AI driver to Drive, via the shortest available path, to the designated Track Mark, Industry or Destination. Switches ahead of the train that are not locked against the AI will be set to allow the train to proceed and reset after the train has cleared the switch. The AI driver will
NOT attempt to find a way around blockages when calculating the shortest path to the Track Mark. All signals and speed signs along the route are obeyed.
Navigate To
Instructs the AI driver to Drive, via the shortest available path, to the designated Track Mark, Industry or Destination. Switches ahead of the train that are not locked against the AI will be set to allow the train to proceed and reset after the train has cleared the switch. The AI driver will attempt to find a way around blockages when calculating the shortest path to the Track Mark. All signals and speed signs along the route are obeyed.
Navigate commands can lead to the consist taking unusual paths to its destination.
Drive commands can lead to the consist becoming "stuck" until the path is cleared.