I'm a domestic relations attorney in Georgia and handle things like child support. I am not aware of any law that limits where a person can travel due to owed child support or alimony. (now someone like me may bring up the fact that he is traveling, regardless of who pays the bill, in hearing related to the back child support) He can be denied a drivers license but should be able to get some form of ID. Assuming we're not talking about outstanding warrants I don't see a problem. However, I have never had this issue come up nor have I researched it.