In a recent study, J. Alexander Maxwell and fellow researchers from the University of Strathclyde’s Urban Design Studies Unit in Glasgow found evidence that before the rise of the automobile, cities developed on a walkable “human” scale, with main streets that rarely exceeded 400 meters (a little more than 437 yards) (the "400-m rule"). Along with Chuck Wolfe, they argue that this uniformity reveals an underlying pattern to pedestrian city settings, which should be considered in contemporary urban design and policies.
Some elements of our urban environments change relatively quickly over time. New shops replace old shops, new buildings replace old buildings, and people come and go. However, other elements are more permanent and often reflect the planning policies, design paradigms, and technologies of the times when they were built. In a sense, these surviving features provide snapshots of our urban histories.
Among their preliminary explorations was a test of the 400-m rule against 100 historically diverse main street networks from cities in 30 different countries around the world. Figures illustrate historic cases, including main street networks from groupings of ancient, medieval, renaissance, baroque, and industrial study areas. Post-industrial cases included main street networks from groupings of Garden City, Radiant City, New Urbanism, and informal settlement patterns of development.
The results of this empirical study suggest that the observational claims behind the 400-m rule are in fact true.
The authors opine that the uniformity of the findings suggests an "effortless" expression of human tendencies – a signature that should be honored by policy and design consistent with this established norm.
Their conclusion illustrates typologies of liveable communities that attempt results that are very similar to the 400-m rule, and provides a call to action:
[M]ore conscious study is needed to tie together past and present. If underlying patterns of human-scale design in urban settings can be captured from historic environments and reapplied in contemporary policy and implementation contexts, then new purpose can be realized from past realities.