my citizens, for unknown reasons, decided to ditch my subway network! in the beginning, i constructed a one-line subway system,(with only 2 nodes/stations) which was used by ppl to commute from residential houses to their industrial workplaces. i expanded the line and added a few more stations along the line, the usage continues, albeit at a very low usage% (highest was at 15% capacity). as my city's streets/roads start getting more congested, i added a few more lines, and eventually made a loop for the subway stations. however, at this point, all the subway commuters disappeared and the car traffic volume spiked up, and i can't get them back to the subways after i de-looped the network. anyone know what's wrong with my subway design? and if there's anything i should know about networking the subs?