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.
A skilled draughtsman guides design conversations by selecting and emphasizing details in a way that computer programmes cannot. Ron Slade, author of Sketching for Engineers and Architects and a structural director at WSP in London, calls it “conversational drawing”. He notes how botany field guides are always based on detailed drawings rather than photographs — as much for what they leave out as for what they show. “Extraneous material that might exist in a photograph is eliminated. It may be important to pick out and illustrate particular areas and leave other parts in sketchy or broad outline.”