I have been taking my dog to prospect park in Brooklyn NY during offleash hours since she was 3 mos old. She is now 18 months. 95 percent of the time everything is okay. But three times now she just ran off and almost went missing good. She also has a habit of just taking off and running into the street if the chance presents itself. What do I do? I have worked so hard to train her and again, most of the times she listens.but she is also very independent and determined when something excited her. And her energy level is extremely high. We have to let her run around 45 minutes a day. She loves to play with other dogs. What advice can you offer?