This is good. But if you want to save even more space: Put them in 45° angle.  Three advantages:

1 You can keep the same c/c as the handle bars don't collide. The angle makes it easier to park and de-park.

2 The width of the row is less.

3 When you take out the bike, you don't block as much.

PS: The picture shows only half of the rack! :-O