>>>I take into account what would happen were I to get a flat and factor in the 20 minutes it would take to fix it.<<<<<

You are much wiser than I am. In all my years of riding and all the miles I've traveled, I've had two or three flats, at the most...and all have occurred in broad daylight. I'm sure I'm due for one just as the sun is going down one of these nights. Thanks for jinxing me.