Rain & Water (Symbol)
Throughout the film, rain symbolizes the washing away of dirt and filth. In the beginning, Travis expresses gratitude that the rain has washed away the actual trash of the city, but rain also comes to symbolize the ways that Travis wants to "cleanse" the city of the people that Travis considers degenerate.
It is not just rain; all water takes on a symbolic value in Taxi Driver. When Travis drives a prostitute and her customer early on in the film, Travis drives through a series of sprinklers, and Scorsese shoots a close-up shot of the billowing waves overtaking the windshield. In a later scene transition, we see a figure in silhouette leaning against an open fire hydrant, which spray large plumes of water onto the street.
For Travis, the cleansing rain that he wishes would clean up the city has Biblical and apocalyptic proportions, a kind of biblical flood. The "cleansing" that Travis wishes for is merciless, separating the good people of New York from the low-life sinners. Thus, the rain comes to symbolize Travis's desire for infrastructural change in New York, a desire for "moral cleanliness," that smacks of gentrification.
Money (Symbol)
The $20 bill that Iris’s pimp gives Travis to keep him quiet is an apt symbol for the corruption of the city itself. When Matthew throws the money on his passenger seat, Travis sees that everything in New York has a price, even the safety of an underage girl. Travis sees the bill as signifying all the filth and immorality of New York, and wants to purify this symbolic meaning. As a result, he does not spend the bill, saving it to pay for the room in which he first confronts Iris about rescuing her. Travis is determined to change the "meaning" of Matthew's money, to use it for ethical means. Additionally, when he goes to rescue Iris in the final scene, he brings her an envelope of bills, hoping that his saved money can help her escape from her sorry situation. In this context, money symbolizes (Travis thinks) Travis's altruism and selfless aid of the vulnerable Iris.
While Matthew's $20 bill is assuredly an important symbol for Travis, his general relationship to money is more complicated. Travis insists that he is not "moonlighting" when he first goes into the taxi depot, and spends his time driving cabs not to accumulate wealth, but to fill his sleepless night. What he does choose to spend his money on is beer, tickets to porn movies, and eventually, illegal firearms. While Travis wants to use money for good, aside from the money he gives to Iris, he himself uses money to fund his various vices. Therefore, money symbolizes both Travis's desire to purify the city, as well as his own participation in the city's filth.
Television (Symbol)
The television that Travis occasionally watches symbolizes the life he cannot have, and the wider public world from which he feels cut off. He watches Palantine's speech obsessively, points his .44 magnum at the wholesome teen dancers on American Bandstand, and curiously puzzles over the high emotions of a television soap opera.
Television mystifies Travis, and as such symbolizes his life of isolation and his inability to integrate with society. From his lone wolf position, Travis becomes jealous of the people on TV for having something that he doesn’t, which only stokes his violent impulses. When he mockingly points his gun at the television, and then later when he kicks the television over entirely, Travis symbolically destroys the social world from which he is alienated, and the life that is outside of his grasp.
Taxi (Motif)
Unsurprisingly, the image of the taxi cab is a motif throughout the film. The film starts with an image of Travis's cab traveling through the white smoke of the city, and ends with Travis driving away from Betsy's apartment in his cab. The motif of the taxi cab highlights the isolation and rootlessness that Travis feels. He drives through the city everyday, watching people go about their lives, but almost never interacts with anyone. The taxi is the fishbowl from which Travis witnesses the world, and the glass windows that separate him from his environment often frame the shots of the film.
Guns (Motif)
The guns in the movie, both real and mimed, are used as motifs to underscore the pervasive threat of violence. The guns represent power to hurt and protection against external dangers, and when Doughboy first asks Travis if he is interested in buying a gun for protection as a cabbie, the viewer knows that guns will become an important buffer between Travis and the world.
Travis uses real guns to murder, but his aggression has a pointedness throughout, even when he is only using his finger. The slow-close ups of Travis’ gun collection show the reverence he feels towards it and his love of violence. The sheer number of guns used in the film portray the ubiquity of violence on the streets of New York.
