I'm not sure about the source of this list, but having lived in 5 states and traveled for work to several more, I believe the worst drivers I've experienced are in TN. Given my current location within TN, I see a lot of traffic from Alabama and can agree they should be included in the top 10. When I relocated from Ohio to TN, I made a comment to my builder about "poor" driving habits of the locals in TN and he agreed...and added that driver's education is not required for teen drivers, licensing exam's are too easy, and roads are not properly crowned (which can induce head-on collisions).
Many years ago, when my son was turning 16 and ready to get his drivers license (not in TN), he had to have Driver's Ed and pass the ground school and road test before being licensed. In addition, I sent him to a Teen Drivers School (a special program offered as part of a private major high performance driving school). Now an adult, he has repeatedly told me that training has saved his life on multiple occasions...primarily because he learned defensive driving techniques and car control. I believe that every state should have a mandatory driver's ed program that teaches those basics.