It's under provincial jurisdiction, but I think the federal government could make recommendations.
In terms of after-school activities, I was raised similarly to you: We were out until the street lights came on and then we went home. Kids played together, and it was okay for us to go to the park, because parents weren't concerned that we were out of sight, but I think your idea about building parks in the centres of subdivisions where people can keep an eye on their children is better.
Maybe there are other measures, such as having, I hate to say, security checks, but something like that, or having safe community centres where children would be able to play.
What do you think about that idea?