I lived on a very large council estate in Essex. For primary school, we were 'bussed' into the closest town. For secondary schools we were more scattered. My Grammar school had few there from the estate, and involved a long walk and then either a bus or a train. Obviously done totally by myself both my parents were working and never had their own car.
I encouraged my children to uses buses when they were still in primary school. The socialist GLC brough in an extra cheap fae for children,, much cheaper than using the car. Although I would admit the first time my 9-year old son went tothe local swimming pool on the bus, I actually followed it in the car and made sure he got off at the correct stop!!!
Back when my children were going off to Uni, it never occured to us to accompany them. They were now 18 years of age and adults. They all managed to get to uni's by public transport for interviews and viewings.
When I was helping out with one of my g.children, I would take her to her orchestra on the bus, talking through where we were, et. By the age of 11 she was able to do this by herself, just getting collected by car for going home.
In London bus travel for for youngsters is easy and free. This encourages teenagers, etc to use this form of getting about. Other areas need to provide free public transport for under-18's