Taxi Driver makes at least a couple of visual references to Stanley Kubrick's 1968 film, 2001: A Space Odyssey. Scorsese's reason for inserting these references, is so that we will deduce that there are also correspondences in themes between the two movies as well.
Top left and right: The colors in Travis's view through the windshield of his taxi (top left), while he's driving on the street at night, are similar to the colors that A Space Odyssey astronaut David Bowman sees at one point, as he moves through the stargate in Kubrick's film (top right). In comparing the colors Travis sees through his cab's windshield, to the colors in the 2001 stargate at the moment shown, we note that the dominant theme of both is one of red-white-blue, with there also being a relatively small amount of yellow in both the stargate and the cab windshield views (the yellow in the latter can be seen at the far right-center of the top left screencap). The red-white-blue from Taxi Driver not only implies that Scorsese is making a reference to America (the colors of the American flag are red, white, and blue), but it's also a hint from Scorsese that the fact that these same colors appear at the point in the stargate shown, means that Kubrick himself is saying something in A Space Odyssey, that has to do with America. Above left and right: The building Iris operates out of (above left) is a reference to the rectangular Space Odyssey monolith (above right).
According to Douglas Trumbull, Special Photographic Effects Supervisor for A Space Odyssey, "[E]ach showing [of A Space Odyssey] draws an increasing number of [hippies], who would probably prefer to just see the last two reels over and over again."[a] These hippies were no doubt particularly interested in viewing the 'psychedelic' stargate sequence, so that they would, as Trumbull put it, "get the trip of their lives."[a] We note that Travis corresponds to these particular viewers, in the sense that he constantly (and thus effectively, 'repeatedly') looks out of his windshield while driving his cab, suggesting the idea of him repeatedly viewing the image in the top left screencap above which, as stated, corresponds to the view of the stargate shown in the screencap to its right. Then, in accordance with this, taking Travis as the metaphorical 2001 movie-goer viewing the stargate, not only does he here represent the hippies, but the fact that he's in a yellow cab is the connection between the yellow in the stargate, and the hippies themselves: In 2001, Kubrick is saying something about the hippies, that has to do with the yellow in the stargate. Noting that most of this yellow in the stargate, at the point shown, is in the form of streaks, and that the term 'yellow streak' is sometimes used to indicate cowardice, Kubrick (and Scorsese, in making his reference to Kubrick) are saying that the historical hippies are/were the 'cowards of America'.
The fact that yellow has contradictory symbolic aspects, indicates that Travis himself is a man of contradictions. This is why he can be a politically-right-leaning man (he wants to 'clean up' New York City), and at the same time, represent a left-leaning hippie (at least, in the context discussed above). Later in the analysis, we will see that there is a 'hidden plot' in the movie, involving Betsy wanting to 'bring out' an 'extremist' element of Travis's two-fold nature.
The stargate sequence in 2001: A Space Odyssey consists, in part, of a series of 'psychedelic' images that David Bowman sees (as he travels rapidly through space), such as the one shown above and the two shown immediately below.
Top left: This image in the stargate is suggestive of green 'slime'. Top right: As described in the Space Odyssey analysis on this blog, the red coloring 'flowing' under the diamond-shaped objects in this shot from the stargate sequence, represents the Styx, a river in the 5th circle of Dante's Inferno (Hell). Above left: The slimy substance on the driver's side of Travis's windshield is a recently thrown egg; it is intentionally made to appear green by Scorsese using lighting effects. Above right: The green and red lights in some of the views through Travis's windshield, such as the ones shown here, symbolically indicate that his movement through the boroughs of New York City at night, represents his movement along the 'stygian sewer' that flows through the city's 'slimy underworld'.
a. Trumbull, Douglas. "Creating Special Effects for "2001: A Space Odyssey"." American Cinematographer. Web, n.d. URL = http://www.visual-memory.co.uk/sk/2001a/page3.html.
b. Dictionary of Symbols, Ed. Jean Chevalier and Alain Gheerbrant. Trans. John Buchanan-Brown. London: Penguin Group, 1996. pp. 1137, 1138, 1139.
