Anti-layout

Anti-layout: A layout whose purpose is to display as many locomotives and cars as possible.

Usage: William's anti-layout held his entire 200 hopper collection.

Source: Bill Schopp first introduced the term in an article, Track Plans for Modelers who hate Layouts, in the October 1958 issue of Railroad Model Craftsman:

...we've departed from the usual and come up with some layouts and percepts with the "anti-layout" car and loco builder in mind. ...

These layouts have had one basic thought: to keep your equipment on the track and off the shelves and out of boxes.

An anti-layout is characterized by having the maximum amount of yard space (possibly including a roundhouse or two) either surrounded by or surrounding a simple loop of track in the smallest possible space that can be accommodated by the modeller's living quarters. 

A good anti-layout design is one that can display every piece of rolling stock in an owner's collection.

Anti-layouts are usually built by modellers whose main interest is building rolling stock.

Mr. Schopp notes these layouts are not necessarily dead-ends:

Most of these ideas can be scenicked and developed into complete railroads in themselves, or into parts of larger railroads.

The anti-layout should not be confused with either the omnivagant or spaghetti layout.

from The Dictionary of Non-Existent Model Railroad Terms, 1st ed., 1959.