Could you also pick up the audio announcements? Could be weird for the app to request microphone permission though, but I think lots of lines have them and shou

Could you also pick up the audio announcements? Could be weird for the app to request microphone permission though, but I think lots of lines have them and should be doable to transcribe them locally on the phone. I think your approach is better and simpler, but as I was reading the edge cases (like someone changing train and going back in the other direction), the audio could maybe help getting from 90% accuracy to 98%. Sounds a bit more involved to implement though.