Through the Subway or Bus tabs:
Go to the Subway or Bus tabs and tap on a station or stop.
Tap the star next to the station or stop name to favorite it.
Through Search:
Tap the magnifying glass on the Subway or Bus tab.
Enter the station or stop you want to favorite and tap on it.
Tap the star next to the station or stop name to favorite it.
A favorite station or stop will always appear on the map (when it’s near your location or purple dot) and in the Subway or Bus tabs' Favorites sections.