The fare restructuring was modified after the coronavirus hit, with a 50 cent increase to the base fare for Travel Wallet riders delayed until at least January.
The move was lauded at SEPTA's online board meeting by Benjamin She of the civic group 5th Square.
"The elimination of the fares for children under 12, and expanding the free transfer to two hours are major advances that show SEPTA is listening,” She said.
City Councilmember Helen Gym said having kids ride free on any SEPTA line will help to create lifelong riders.
"Making transit accessible and therefore habitual for youth encourages future investment. I can say that as a mom of a 20-year-old son who has yet to get his driver's license,” Gym said.
The new fare plan takes effect next Wednesday.