Alternative modes of transportation were available. But transit riders cannot be taken for granted. When poor maintenance began causing major delays, the system became unreliable. As it no longer met the needs of the commuter, large numbers defected to using their cars. As maintenance improved, customers returned.
Time is the most critical factor in the commuter's decision process.
The longer the commuting distance, the greater the opportunity to greatly reduce travel time. Dependability is essential to customer satisfaction. People dislike waiting at a transit stop. Actually, it is the uncertainty as to when, or if, their transportation will arrive, rather than the waiting, that is the problem. In Europe, one can set their watch by the train schedule.