My article “Off the Grid… and Back Again? The Recent Evolution of American Street Network Planning and Design” has been published by the Journal of the American Planning Association and won the 2020 Stough-Johansson Springer Award for best paper. It identifies recent nationwide trends in American street network design, measuring how urban planners abandoned the grid and embraced sprawl over the 20th century, but since 2000 these trends have rebounded, shifting back toward historical design patterns.
This study measures the entropy (or disordered-ness) of street bearings in each street network, along with each city’s typical street segment length, average circuity, average node degree, and the network’s proportions of four-way intersections and dead-ends. It also develops a new indicator of orientation-order that quantifies how a city’s street network follows the geometric ordering logic of a single grid. These indicators, taken in concert, reveal the extent and nuance of the grid.
Thinking [in terms of loops and arcs] allows us to let go of a specific journey or sequence, and imagine dozens of scenarios and possible sequences in which these skills can be learned. This doesn’t mean there aren’t more fundamental skills that other skills build upon, but we can let go the tyranny of how, precisely, a person will move through a system. We’re free to zoom in and obsess on these loops, which does two things for us:
Approach the design of a system as the design of these as small but significant moments of learning.
Consider the many ways these loops might be sequenced, with the exact order being less important.