Did you know there's a map of the public toilets on the highways across Canada? It's put out by The Powder Room, a national education program for people with overactive bladders, but when you're out there in the middle of nowhere with several cups of coffee sloshing around inside, any bladder can be overactive.
And if you're like half the population and lack exterior plumbing, simply stopping by the side of the road isn't always a viable option. You can find information on the map by clicking here.