What is the fastest way for me to realisitically drive from miami to san diego. i want to push it, but dont want to fall asleep at the wheel. Will I have to pay any tolls?
I never drove the stretch between SD and Phoenix, but from Phoenix, I suggest you take I-10 (no tolls) then, in Florida you can take I-95 to Miami. It's fast, no traffic or very few (maybe in San Antonio, Houston, and Mobile in rush hours). I'm not sure but I don't remember paying any tolls on I-95 on that stretch (between Jacksonville approx and Miami). Or you can also take take I-75 (FLA west coast) and then go through the Everglades (there's a toll booth when you enter the Everglades but it's not very expensive).
Phoenix-Miami could easily be done in 4 days if you're used to drive long distance, depending on your experience. Roughly I would allow 5-6 days for the whole trip but maybe someone else who did the entire cross country trip could help you better. The whole trip is 2661 miles long, so if you plan on taking 5 days to make it, you would have to drive approximately 532 miles per day. If you take 6 days, you would have to drive roughly 443 miles a day. Of course, you'll probably run through some road construction and you have to allow a few hours each day for eating and sleeping. Getting from point A to B is ok, but stop and visit is so much better, if you could get a few extra days for your drive, it would allow you to see so much nice places. San Antonio and New Orleans, for instance, are must sees, lots of entertainment and things to do. You could also spend some time on the Texas or west Florida sea coast.
As soon as you feel tired, stop and find a motel room or campground, if you can't at least take a little walk outside in a rest area or lock yourself inside of your vehicle and have a little nap, chew gum, drink coffee and/or play loud music, anything that'll keep you awake for a while but don't surestimate your capacities especially if you're roadtripping alone.
Have a great trip!