Second film directed by Mike Nichols.
The ending is a favorite of mine. Music slowly comes to a halt when the car runs out of gas. Ben starts to run toward the church with no musical score - you can only hear the oncoming traffic which in turn adds to the intensity of stopping the wedding - only after the couple settles down on the public bus does "the sound of silence" play. Just as it did in the beginning of the film.
During the running sequence it also looks as if Ben isn't going anywhere in life literally and figuratively. Nichols shot the action with a long lens which flatten the perspective onscreen.
When running to the bus the couple seems content, even laughing. It's when they board the bus and look back that their smiles slowly start to fade, and start to realize the consequences of their actions. Separating themselves from their folks they are riding away into an uncertain future - did they make the right choice?
I probably would have ran to the bus with Ben too. With brash and irrational actions are extremely seductive.