Why does Ember parent route's actions wont get triggered?

Router

this.route('administration', function() {
  this.route('users', { path: '/' });
  this.route('users');
});

routes/administration.js

actions: {
    didTransition() {
      console.log('administration didTransition');
    }
}

routes/users.js

actions: {
    didTransition() {
      console.log('users didTransition');
    }
}

When go to url: localhost:3000/administration/users

users's didTransition got called, but administration's didTransition wont get called, can anyone help me on debugging it or the relationship between parent/ children routes?

I'd like to know which lines of code caused such? Thanks.