Welcome, and good luck on your scramble from the big, smoggy mess that is Phoenix (I do't mean to offend, but every time I've been to Phoenix has been very smoggy and unpleasant for my asthmatic lungs--I'm glad you're getting out!)
I spent a fair amount of time thinking about how you would leave Phoenix in the SHTF situation. I lived there for a total of 6 years and just left there last year. I did a lot of hunting and fishing North of town and would be pretty confident that you could get all the way to highway 40 by nearly avoiding pavement altogether. So many trails and open spaces to be had if fuel were not an issue. The 17 would be a parking lot in less than 20 minutes of if the nuke plant melted down.
Thanks so much for all of the support. I get up every day excited to see what else I can find out about survivalism. Then try to apply it to my life. This forum has been great so far. Very educational! Thanks again!!