Metro Ticket

Metro tickets are miscellaneous items in Fallout 3.

Characteristics
Metro tickets are requested at any metro station in the Capital Wasteland that still has active protectrons. Having a ticket can prevent one of these robots from becoming hostile. These protectrons are inactive by default, but can be activated if the player can hack a nearby terminal as they then come out of their capsule and search the area for hostiles and passengers (you if you have a ticket). However due to the protectrons slow walking you can simple flee before they get the chance to scan to avoid combat

Locations
Metro tickets aren't found in abundance around the wasteland except in Metro stations, but if the add-on Broken Steel, as many as 50 tickets can be found scattered throughout the Olney Powerworks. In one section of the Powerworks, there is a desk with a stack of Metro tickets that are assembled in a traditional triangular card stack.

Some feral ghouls in the Metro tunnels carry tickets, implying that they were passengers before radiation transformed them into ghouls.

Bugs

 * Sometimes when the protectron scans the player for a ticket, it will not detect the ticket(s) in the player's inventory and will become hostile.