When you gotta go, you gotta go.

But if your only option is a scuzzy cement-block room in the back of a gas station you might think twice about how long you can hold it. Especially if you're traveling with others and you've already used up your alloted number of bathroom breaks.

Here's a solution: www.thebathroomdiaries.com. Before you snap your seatbelt, check this site for safe, clean restrooms along your expected route -- just in case. Or, print them out and bring the list along.

If nature's call catches you off guard and you find yourself pleasantly surprised by the facilities, add it to the list and help out another traveler.