When my oldest son was learning to drive, he told me that he was happy to drive whenever I was tired. But coaching a new driver is exhausting. If you normally "drive" 100 yards out, checking for traffic and other obstacles, with a new driver you have to drive 200 yards out; the extra distance is needed so you have time to process and verbalize and they then have time to respond appropriately. And you have to retain enough energy to respond helpfully when they make a mistake, instead of blowing up. So it was easier for me to drive when I was tired. Now that his driving is now good enough that I can let him drive when I don't feel like it, he is heading off for college in August.
When my 15-year-old finished driver's ed, the 50 hours that he is required to spend driving over the next six months seemed easy to accomplish. But then reality set in. Most of the time he is in the car with me, we are driving in tourist traffic and construction zones, and he only wants to drive if he is alert (which I appreciate). If I do drive in quieter parts of town or out of town, either he isn't with me, or we are in a car with a stick shift, or I am too hurried or tired to let him drive. As a result, we aren't getting the 20 minutes a day that we should be averaging; I guess we'll have to start setting up drives just for him, instead of trying to fit it into our day. With all the driving I do in a week, it baffles me that I will have to add more driving in order to give him the experience he needs. But since my other back-up driver is leaving in a month, I am motivated to make sure I have a replacement driver as soon as possible!