Dream About Driving A Truck With Sister

I had a dream where I was driving a truck with my baby sister but the car was driving itself and I had the fear of crashing it onto ongoing traffic. We just kept driving on a very long road, roads that I know irl and some that I made up. I only had control of the steering wheel from where I was sitting because my sister was in the middle so getting to the breaks and accelerator was hard. But while we're driving I decide that we will stop at my grandmas house. In the middle of driving there is a hilltop and the truck slows down, so I get worried because I don't wanna get honked at, but noone honks and I keep driving. I decided to put on the hazard lights and pull over so I could drive. This means that I could actually use the breaks from where I was sitting. I realize that we drove past my grandma's house. When the truck stops at a remote location, I go out of the car to sit in the driver's seat and the dream ends.