What's the appeal of 2-up?
-You get to share an adventure!
-You get someone to cuddle with in the sleeping bag at night
-The passenger can be on the lookout for the turn, the motel, the restaurant, the gas station, while you negotiate the traffic.
-If things start going to shit, one of you can maintain the quiet voice of reason and calm.
-If you don't have room for all of the dessert, you can share it.
-You can relax in the shade while the passenger goes from motel to motel to get the best deal.