Also, public transit systems are very safe during commuter hours. That’s when they work best. If I were a parent, I would not be concerned about letting my children take public transit / walk home as a group during 3-4pm. The city really is filled with other kids doing the same thing.
This was my life as a kid. It was wonderful. I made and maintained some of my best friendships literally just going to or from home on the subway with schoolmates.