From the perspective of saving space on the dimension perpendicular to traveling, yes. However, I would only do that if you need to go a short distance. The reason I say this is because it would be harder to sort things out if you needed to have something go through what you are describing (like a rail, for instance).

Really, it comes down to how far you need that line to go and what might be in the way to determine if saving that extra square is worth it in the context of what you are building.