"If you don't interact with them, then why do you drive fast on an empty highway? Why don't you inch forward instead as if there were cars around you?" he sneered.
"Interacting doesn't mean talking. Acknowledging the other's existence, and behaving accordingly IS interaction".
"As long as you are interacting, you are communicating. As long as you are communicating, you are in a relationship with each other."
It is only when you do not notice the other car coming towards you that you do not acknowledge and interact with it. And that is when there is no communication.
Until the car slams into you, causing you to acknowledge, interact, communicate and now have a relationship.