'Joining' a train

[Hundredacrewoods]

I've recently heard train station announcements inviting passengers to 'join' the train once it has arrived. Is 'join' really the correct verb? 'Board' sounds more natural to me.

Board is the word. You can't join a bloody machine.

It's probably meant to be inclusive and empowering, or something.

'Board' is correct of course.

But I think 'join' isn't completely wrong. I can't articulate exactly why, though I've had wine & I'm tired

I think they use 'join' when passengers are boarding a train partway through its route rather than at the start. In that context it makes perfect sense to me - you're joining the journey, joining other passengers already on board.

Errol nobody "joins" a journey.

They could say "Join us on our journey"

But why bother when "board" is correct no matter which stage of the journey we're talking about?