A transit pass was a piece of identification used in the 21st century in the United States of America, used mainly to identify the homeless.
After arriving in the year 2024 due to a transporter accident, Commander Benjamin Sisko and Dr. Julian Bashir were asked by Vin if they had an identification card, such as a UHC card or a transit pass. Since they had none of these on them, Vin and his partner, Bernardo Calvera took both Sisko and Bashir to the Sanctuary District in San Francisco. (DS9: "Past Tense, Part I")