Creating Visual Symmetry
Shown above is a 1940's topo map of Frederick, MD. Note the general sense of order, the ninety degree grids, and structures oriented perpendicular to the axes.
Humans are wired to prefer visual symmetry. That applies to infrastructure as well. Whether it be streets, railroads, or structures, we generally prefer a more grid-like format with a limited number of axes. For our purposes I'll define an axis as a line such as a street, building face, or right-of-way.
When it comes to layout design, there is a greater sense of balance when there are a limited number of axes, structures are oriented at ninety degrees to them, and elements are mostly at ninety degree orientations to one another.
On the flip side, when you have numerous axes, at a myriad of angles, and structures plopped down salt and pepper style, you end up with visual chaos. The composition appears toy like.
The example above shows a typical peninsula. Without the guardrails of a straight fascia, it's easy to get in trouble. In this case the main problem is the orientation of the structures with respect to the axes created by the road. There's just way too much going on directionally.
Here, we've made order out of chaos by reducing the lines to just two axes and orienting the buildings to them at ninety degrees.
Here's an example of the same problem on shelf style bench work. Too many axes. Too much chaos.
Using the same shelf as an example, the above shows a cleaner composition. We can get away with the two roads being at different angles because we still have so many elements oriented at ninety degrees.
For more in depth discussions on design composition, check out my book, Model Railroading As Art.