If the horizontal is more then 1/3" the vertical, you have to go up one pipe size.
Most homes have the plumbing toward the back, thus that's where the vents are. How many kitchens have you seen facing the front street?
Or bathrooms for that matter. If when Plumbing, I'm near the centerline of the home, and I can jog a few feet to be at the back, I sometimes do that.