The Railroad The Railroad is an underground movement with a primary aim of freeing sentient synths from their creators at the Institute . " Background " . " Fallout 3 " . There is little available information about either the Railroad or the Institute , but the Lone Wanderer becomes involved in their conflict during the quest The Replicated Man in Rivet City , where a scientist named Dr . Zimmer requests aid in capturing a runaway android , and Railroad agent Victoria Watts pleads with the character to take pity on the android and fake its / his death . The Railroad ' s methods for aiding in escape can be extreme , going so far as to find doctors to perform full facial reconstruction on escapees . They are known to operate in the Capital Wasteland and at least as far north as the Commonwealth . Dr . Zimmer , Ms . Watts , and the android give very logical and convincing arguments for their point of view , and the player character must make an ethical choice based on the limited information they gain from each of them . There are multiple " good Karma " solutions . " Fallout 4 " . The Railroad is a joinable faction situated in the Commonwealth who assist runaway synths . Their main command center is located in the Old North Church in Boston , after their previous base was compromised following a raid by the Institute . They maintain a network of safehouses and clandestine contacts reminiscent of their namesake , the 19th century Underground Railroad , which helped slaves escape and reach free areas . To remain covert , members use a special marking system called " Railsign s " to mark cache , safehouse , and dead drop locations , as well as the presence of allies and / or danger . The Sole Survivor can learn about the Railroad through a few media . You can investigate the area around Park Street Station , speak with Doctor Amari at the beginning of The Molecular Level who indicates that the Railroad would be helpful to your cause , or overhear people in the Diamond City market , the Dugout Inn , or guards in Goodneighbor discussing the elusive Railroad . All of these will result in the Sole Survivor getting the quest Road to Freedom . Piper also makes comments about them after the The Glowing Sea quest starts . The Railroad is joinable through the " Fallout 4 " quest , Road to Freedom . Membership in the Railroad may negatively affect relations with other main factions . The more quests the Sole Survivor does for the Railroad , the more the Institute and the Brotherhood of Steel will disapprove of their actions . If the Sole Survivor sides with the Brotherhood of Steel or the Institute , they are sent to exterminate the Railroad , believing that they will try to stop them . Relations with the Minutemen are not affected by joining the Railroad . However , when completing the Minutemen version of The Nuclear Option the optional mission must be completed or the Railroad ( including Deacon if he is your companion ) will become hostile when the player next speaks to Desdemona . You will still be able to accept A Clean Equation missions from P . A . M . , Lost Soul mission from Doctor Carrington , and even the To the Mattresses missions from Desdemona when Drummer Boy notifies you . Any extra attempt to speak with her outside accepting and completing quests will cause the Railroad to become hostile . This appears to be a bug as the Lost Soul missions should not be available if you left no survivors at the Institute . Appearances . The Railroad appears in " Fallout 3 " and " Fallout 4 " .