I remember a few months ago I was driving to work. When I drive to work I have to drive 25 kilometers to the city, so going to work and back eats up 50 kilometers from my car.
Unfortunately for me I drank too much water before leaving home. Because of this I was busting to urinate while on the way there. The problem was that I didn't know where the toilets were. The traffic was also very bad.
I arrived at work just in time, rushed to the toilet, and relieved myself.
Learning from my mistake, today I have thrown an empty 2-liter plastic milk bottle in the back seat of my car. If I ever have to urinate during a trip I will pull up at a deserted residential street and urinate in this milk bottle.