What is the main conflict in Driving Miss Daisy by Alfred Uhry?

Daisy Werthan is a Jewish widow who shown from age 72 until 97. Her chauffer, Hoke Coleburn, is a black man who ages from 60 to 85. The third character, Boolie Werthan, is Daisy's son. He is 40 years old when the play opens. Although this is a one act play, the action shifts frequently as the characters are seen changing over the course of 25 years. The play explores the strange connection between racism and true friendship.