She's on a 6 foot leash on our walks and just does a quick lunge after the bigger vehicles (usually almost knocking me off my feet). I give her a leash correction and then she comes back to my side. She usually does this at the beginning of walks when she hasn't worn off much energy yet. The look on her face tells me she thinks this is a very exciting game. The kids on the buses waving and calling to her don't help either...She loves kids.