I travel a lot too. A good bit is the same long stretch of road. And there is no way I can make the 8 hour drive without having to piss. Call me weak. Lol Like Gotthegoods said, I have found the good and bad exits. One trick I use is that in a brightly lit glossy tiled bathroom, the tile almost becomes a mirror. Even if it is not totally clear you can identify movement behind you. I do often opt for the stall though. Remember most of the doors will swing both ways after someone gives it a good kick. So if you are aware and see it coming, that door might just be best weapon to use first. Lots of my destinations limit what I can have on me and in my car, so sometimes you have to use your surroundings. And no, we are not paranoid, we are careful.