Kids say the craziest things

Today, the four of us were out running errands all morning. At one point, Deker was getting pretty hungry, so we found a shady area so that I could nurse him. While we are sitting there, Keagan started getting pretty impatient so Andrew was trying to play with him to keep him occupied. After sitting in the car for a little bit, Keagan started pointing out the window and saying "Daddy, road, hit the road". Andrew and I both started doing the silent laugh thing. I just couldn't believe what I was hearing and I wonder what he would have done if I let him out of his car seat. Did he realize that it is just a figure of speech?