|For the Fallout and Fallout 2 items, see Pass key.|
Blue pass card (left) and red pass card (right)
A simple encoded transit pass for the pre-War District of Columbia Transit Authority metro lines, entitling the user to unlimited travel on the matching metro line. Protectrons used by the DCTA in lieu of human workers were programmed to scan for pass cards and let passengers pass through if they possess one matching the line's color. This functionality persists well after the Great War, though Protectrons now respond with deadly force if the user doesn't have the correct pass card.