Is there free transportation services for the elderly who need to get to a doctor's appointment?

My mother is dying from cancer, lost her husband 10 months ago, is legally blind from macular degeneration. She is living alone at home. Her oncologists, who had an office nearby, now has only offices hours at a location in many miles from her home. She's relied on friends to drive her to appointments but doesn't have anyone who will take her to the new location. I live in another state and can't do it myself. She's heartbroken if she can't continue to see her current oncologist and has to find a new one. Her cancer is terminal and I'm doing all I can to keep her will to live going.