Here's a suggestion that will not mess up your original operating scheme, but will give you more aisle space. Turn the switch around in the lower right hand corner and make it a left hand switch. You eliminate one unnecessary loop and still have two tracks headed up to the top part of your drawing.
Next, take out one piece of straight track on each side running up to your reversing loop and you should have at least 18 inches of aisle space to work with.
Chuck