Uncle Al works in the taxi cab garage. He is not an uncle to any of the Russo kids by blood, but is called Uncle by Alex. Uncle Al's only appearance is in "Taxi Dance".
History
Uncle Al appears to have been driving cab #804 when Theresa went into labor with Alex. He remained close with the family over the years, and even calls them to let them know that cab #804 will be retired. His interactions with Alex, such as pinching her cheeks, show that he has taken on the "uncle" role, and cares for Alex as if she were family. Though Alex was humiliated by being babied in front of harper, she was touched.