Couples should feel OK to zone out as well, she says. "Traveling together is different even than living together, and so setting your expectations accordingly is important," she says. "When you're traveling, there's a lot more compromise required, there's a lot less personal space and you're subject to each other 24 hours a day ... Don't be hard on yourself if you find that you're starting to bicker. All that means is just that you need a little more alone time."
Betsy and Warren Talbot seem to have mastered that technique on what's become a permanent road trip. Propelled by health scares that happened to a friend and sibling, the couple decided not to put off their travel plans for retirement. Before turning 40, they ditched their house and jobs in Seattle (he worked for Microsoft, she consulted for small, women-owned businesses) to travel the world with nothing but each other and what they can carry on their backs.
For an upcoming house-sitting excursion to the United Kingdom, they've already discussed that Warren will hike while she works on her book project. (The couple chronicles their lifestyle on the website MarriedwithLuggage.com.) "He knows every day that I'm not getting up at 6 a.m." to hike, she says. "We do that everywhere we go."
They've learned the art of compromise and to share the plethora of decisions. "When you're on a road trip, everything is a decision," Warren says. "Where am I going to eat? Where am I going to sleep tonight?"
The lack of literal stuff between them has had a freeing effect to spot and solve issues when they arise, let them focus on what's important – and leave room for adventure.
If you know money, family you're visiting or even how messy the car gets is going to be a trigger, then you set expectations and even an escape hatch, Bonior says. To stop an argument from escalating, some couples pick a word, sometimes a funny one, that signals time to separate and calm down. "The key is that you worked that out in advance," Bonior says, "and you agree on it."
Luckily, for a road trip, comedic references are plentiful. Borrow a line from the movies "National Lampoon's Vacation" or "Road Trip," and you're likely to diffuse tension – and realize, by comparison, just how well your own road trip is going.
[Read: How to Control Road Rage.]