Are couples that commute in the same direction happier?

Yes:

Couplesâ marital satisfaction can depend on whether they commute to work in the same or different directions. Two surveys, conducted in the United States and Hong Kong, showed that partnersâ satisfaction with their relationship was greater when they traveled to work in the same direction than when they traveled in different directions. This was true regardless of whether the partners left for work at the same or different times. A controlled laboratory study eliminated alternative interpretations of the survey findings, showing that even randomly paired participants reported greater attraction to one another when they walked to an experimental task in the same direction rather than in different directions.

Source: “Going my way? The benefits of travelling in the same direction” from Journal of Experimental Social Psychology