I do want to add another possible option, but perhaps I was (un)lucky:
One time only, I had a teen sim who was out fishing past curfew. She climbed into her car to go home, but the police did not bring her home. Instead, she was removed from the family entirely.
However, I've had teens who hit the curfew mark while on their way home in a taxi, and nothing ever happens.
My children and teens are no longer allowed to visit friends after school, and if they are doing an afterschool opportunity or activity, I queue them to go home automatically.