I'm currently on a road trip with my friend and I'm going to take his car and go home.
Is there a reason you're going to take their car?
I just decided that road trips aren't for me.
Taking your friend's car is stealing and you could get in trouble if you take it. If you really must return from the road trip, you should rent a car, get an Uber, etc.
Yes, I understand I shouldn't take his car just because I don't like road trips.
I'm glad you realize this because if you took your friends car, he would have no way to return home as it's the car he's using for the rest of the trip and his return. Have you considered just sticking out the road trip? It might end up becoming a lot more fun than you think.