I am going to take four scene from the taxi driver and show how the mise-en-scene, cinematography, and editing support Travis Bickles state of mind and personality.
First I want to state what Traviss state of mind and personality is throughout most of the film. Travis is isolated from the rest of the world. He feels like he does not fit in with the rest of society. He is looking for a direction, a cause, a reason for his existence and he takes the Taxi job as a way to cope with some of that frustration.
The first scene I want to analyze is the one of Travis first applying to become a taxi driver. To help reinforce Traviss isolation from the rest of the world, Travis and the interviewer are in separate framing throughout most of the scene. His answers come in either short or stuttered responses. We find out from the interview that Travis had been in the Marines. Travis is still wearing his old marines jacket. We get the impression that the last sense of belonging Travis felt was when he was in the marines. The framing is tight using only medium and close up shots of Travis and the interviewer, keeping Travis away from the rest of the world. There is only the diegetic sound of the taxi garage, no music is playing. When Travis is exiting the garage the camera leaves him and does a panning shot of the garage almost like he is so isolated that the camera itself can become detached from him.
When Travis exits the garage the framing becomes much looser. Extreme long shots are used making Travis seem even more isolated from the few people on the street. We then come to Traviss apartment. While Traviss voice over is heard speaking about the rain coming and washing away all the filth and scum on the streets we are juxtaposed by the scene of his apartment. His apartment is a visual contradiction to what Travis is saying. There is trash every wear. Clothes are thrown and hung anywhere in no particular order or method. There is a stack of magazines on his bed. All the clutter in his apartment gives us a window into Traviss state of mind.
There is now a cut to Travis in his taxi. It is night time and we have none diegetic soundtrack playing. Interestingly for the most part the soundtrack only plays when Travis is alone or in the taxi. This again reinforces the sense of isolationism that Travis is feeling. Traviss voice over is still playing as there is a tracking shot from the taxi as it drives along the looking at the side walk. All the people Travis is speaking about are walking on the sidewalk. After Travis speaks about the lowlife that walk the street with obvious contempt he says that it doesnt make a difference to him. Travis stops to pickup a man and a prostitute. All the shots are medium shots from the front seat looking in to the back. This again keeps Travis in Isolation from the people he drives. Like he is looking into a window and seeing other peoples lives. He has no conversation with the people he drives. He only watches them as he takes them to their location. At one point he goes through street that has water raining down on it from an open fire hydrant. The water completely obscures his vision from the front window and he turns on his windshield wipers to wash it away. This again is reinforcing his state of mind being at odds with everything and wanting to wash it away.
The next scene I want to analyze is that of Wizards court. Where Travis goes in to have a cup of coffee with Wizard, Doughboy, and Charley T. The scene opens with the camera panning to fallow Travis from inside the cafeteria while he walks in. The film switches to a medium straight on angle shot as Travis sits down on the extreme right of the frame. This is showing how far away he is from the rest of the taxi drivers and the world. As Wizard and Doughboy have their conversation Travis is kept in separate framing or he is kept in the back far right of the frame and out of focus.
When Doughboy asks Travis a question, Travis is preoccupied at staring at the black pimps. The camera leaves Travis and does a tracking shot over to the two pimps sitting at the other table while Doughboy is heard in the background. The camera finally pans back to Travis as he finally hears Doughboys question.
Even while he is answering Doughboys question Traviss attention becomes diverted, as the camera cuts to a high angle close up shot of Travis opening a bottle and dropping a tablet of Alka-Seltzer into a glass of water. As Doughboy is speaking to him the sound is turned down and Doughboy can be barely heard over the sound of the Alka-Seltzer fizzing. There is a low angle zoom-in close up shot of Travis as he stares at the glass and the it changes back to an extreme close up of the fizzing glass. Traviss thoughts are completely consumed by the glass as we get the feeling that his mental state is much the same as that of the fizzing glass.
After an extended period of time the camera finally comes back to a medium shot of Travis and Doughboy who is now on the right side of Travis. Doughboy is standing over Travis and crowding him into the lower left hand corner of the frame. This probably resembles Traviss mental state as he probably feels crowded and uncomfortable with having to talk with Doughboy especially with him so close.
After Doughboy leaves there is an uneasy silence between Travis and Wizard & Charley T. Travis is again put in the very far right of the frame and now seems even further away and isolated from the other two now that there is an empty seat between them.
The next scene I am going to analyze is where Travis drives a man (played by Martin Scorcese) up to a curb and watch the mans wife in the window. The scene opens with a medium tracking shot following the cab as it pulls up to the curb. It then cuts to the interior of the cab as Travis stops the meter thinking that the man is ready to get out. The man however does not want to get out and wants to keep the meter going. The shots through out this scene are either from the back seat look at the back of Traviss head or from just outside the front windshield looking in.
The man consistently tries to engage Travis in conversation about his personal affairs. Travis never turns around to look at the man he only will look at him through the rearview mirror. This reflects Traviss desire to keep a distance from his customer and prefers to see him only as if looking through a window. As the man directs Traviss attention to the lighted room in the apartment building the camera changes to a first person slow panning shot as it scans the Apartment building looking for the window. Finally Travis sees the room. Conversation for the most part has been one sided with Travis giving only single syllable answers to the mans barrage of schizophrenic questions. When the man tells Travis that he is going to kill his wife with a 44. Mangum Travis starts to take something of a morbid interest in what the man is saying. This is supported by the camera shooting from the back seat from a medium low angle as Travis adjusts his rear view mirror so that he can look at the man. Traviss face stays about the same but his interest continues as he starts to formulate a plan in his own mind.
He listens even more intently when the man talks about blowing away his wifes face however his attention becomes diverted after the man starts to talk about shooting a womans pussy. The reasoning for this would be that he is looking to clear away the evil thoughts in his head and the desire to shoot himself would take care of those evils. The volume is turned down slightly towards the end of the scene as Travis starts thinking about his own plan. This will be supported a few scene later when Travis wants to buy a 44. Magnum.
The final scene I want to analyze is the final scene in the movie. The scene opens with a tracking shot of newspaper clippings hanging up on the walls in Traviss apartment. While the camera is tracking Iriss fathers voiceover can be heard until the camera finally rests upon the letter that the voice is reading from. The scene then changes to an long exterior shot of the diner. The camera cuts to a medium shot of Travis, Wizard, and Doughboy all standing around a taxi. They are standing fairly close together and Travis doesnt seem so isolated from the others. Wizard tell Travis that he has a customer and Travis goes over and gets in to his cab. The scene cuts to the Interior of the taxi as Travis drives Betsy home. He is smiling confident as Betsy seems to have a renewed interest in Travis. However Traviss sense of isolation is apparent as Travis and Betsy are kept in separate framing. Travis only engages in light conversation with Betsy and does not charge her for the ride in some sort of personal revenge on her.
As he drives away it becomes apparent that Travis is not better as he starts to look around in a nervous sort of fashion. The final shot is from the back seat. Everything else is blurred except the rear view mirror which show Traviss eyes as he looks around with a Feral expression.