I bet you care about humans, both your offspring or not lolI care very much (what if it is my kids on the parking lot!)
So far none of the actions by the car, in my summon attempts, have made me abort the session.
I think a better way to rephrase my question would be: do you wait until the path is 100% clear before you summon? Or are you comfortable with some light/medium/high traffic between the car and yourself?