I suspect most people think port and starboard are just synonyms for left and right. I did for a very long time. And you also have to consider non-native speakers who might not know the nautical terms at all.

The trains where I live say “on my right” and “on my left”. It sounds a little weird hearing an automated voice speaking in the first person, but it’s concise and gets the message across to people who won’t know nautical terms.