(Portland, OR) -- Riding TriMet, C-TRAN and Portland Streetcar will be free today in honor of Rosa Parks' Birthday. In December 1955, Parks refused to give up her seat on a bus in segregated Montgomery, Alabama. She was arrested and fined for her act of civil disobedience, and the incident inspired a federal lawsuit that led to the desegregation on all public transportation in the U.S.