Crossing a new milestone

O.K...so I am officially "FREAKING OUT" right now...my 'baby' (Josh, that is, who is 16) is taking his class today so he can get his driver's license. Next week he will begin his 6 hours of Behind the Wheel and then takes his test. I am so NOT READY for this...I much prefer dealing with the toddler trauma. I know it will come in handy, and he is so responsible...BUT I also know I will be calling him and wanting to know where he is all time too. Is that bad??? He is ONLY 16...I don't know how much I can "let go" yet. I can see it right now, "Hold on guys, my 'mommy' is calling to check on me."...really! I know I can't do that... but how do you let your baby just go off in the world by himself??? I think I'm going to cry...