From what I've read, my road running problems were still mainly to do with my shoes. I had always purchased "good" shoes, but they weren't appopriate for my weak arches, so I was still getting hurt. Have you been evaluated by a running expert or podiatrist? Maybe some orthotics would help?
I've gone back to the treadmill, but now that I have new (supposedly appropriate shoes) I plan to try the roads again. Otherwise, everyone tells me to run on trails. Bike trails, hiking trails, trail trails trails. Which I haven't tried yet, and sounds like isn't really an option for you, anyway.