In the past few days I have attended three presentations about designing successful public spaces, two at ABX and one sponsored by Massachusetts Smart Growth Alliance. I learned a new word, thigmotactic. A strict definition is something like contact-loving, but in the context of placemaking it is generally used to mean edge-seeking. When selecting a place to stop and rest, people, and apparently most animals, head for the edges of an open space. This is a behavior long cultivated by evolution. If you sit with your back to a wall, no one can sneak up behind you. And an open space in front of you gives you a good command of the general goings-on. There is an ideal size for an open space, about 300 feet by 400 feet. At this scale whoever or whatever is nearby or approaching can be evaluated from a safe distance. At 300 feet we can recognize a face; at about 85 feet we can recognize an emotion on that face, in time to prepare for any eventual interaction. That this size is optimal is born out by the measure of popularity of existing urban open spaces throughout history.
Thigmotaxis has been observed in the behavior of people in open spaces for hundreds of years. We are only now starting to understand some of the hard wired cognitive processes involved and why this matters in the design of open space. Other important features of successful open spaces include a sense of enclosure or limits to the space, (providing those edges), places to sit, access to sunlight and shade, elements from nature like trees or plants, and water, options for food, and entertainment (biophilia). All of these features together provide a place that will be attractive as a place to stop and rest, creating the most important characteristic of a public space, opportunity to watch other people. For as much as we seek defensible space, we also seek contact and interaction with others, which is why we need well designed public spaces.
These presentations were particularly relevant to a project I am currently working on for the Marine Corps Community Services. Along with a larger team of financial, food, hospitality, and partnership experts, we are analyzing the array of facilities and services available to marines. Our goal is to improve the quality of life on base through strategies that are also financially sustainable. We hope to be able to use recent research in open space design to create or improve the open space on installations to provide places where the population can gather informally, get a few errands done, relax, play, and socialize.