A helpful book excerpt from ULI’s Urban Land magazine:

This is an excerpt of the book “Pedestrian- & Transit-Oriented Design,” co-authored by Reid Ewing, renowned urban planning expert and University of Utah research professor, and Keith Bartholomew, professor and associate dean of the College of Architecture and Planning Ped and Transitat the University of Utah. The book operationalizes nearly a half-century of urban design theory in ways that provide practical meaning and use to urban planners, planning commissioners, city council members, developers, and citizens who desire more livable environments.


Here’s an excerpt from an excerpt:

Jan Gehl (2010) demonstrates how distance plays a determinative role in personal interaction and hence designing for the human scale. At 300 to 500 meters (330-550 yards), humans can identify other people as humans, instead of objects.

From 100 to 25 meters (110-27 yards), individual characteristic and body language can be observed. After 25 meters, people enter a “social” field of vision where “richness of detail and communication intensify dramatically meter by meter” (p. 35). Gehl then breaks the distances into four categories:

  • Public distance >12 feet
  • Social distance 4.5-12 feet
  • Personal distance 1.5-4.5 feet
  • Intimate distance 0-1.5 feet

According to Alexander, Ishikawa, and Silverstein (1977), a person’s face is just recognizable at 70 feet, a loud voice can just be heard at 70 feet, and a person’s face is recognizable in portrait-like detail up to about 48 feet.

These distances set the limits of human scale for social interaction and, by extension, how space is designed. Gehl notes that the most noted public squares in Europe are almost all smaller than 10,000 square meters (100 m ×100 m); most are smaller than 8,000 square meters.