Until a vaccine is found for COVID-19, and perhaps beyond, it will be important to practise physical distancing in towns and cities.
Whether this is possible will come down to the “carrying capacity” of the urban infrastructure: in particular, the relationship between Pedestrian Supply in the form of sufficiently wide footways and Pedestrian Demand in terms of the need for people to walk, whether that is to work, home, school, the shops or for leisure and pleasure.
Both supply and demand are calculable using tools from tape measures to multi-variable modelling algorithms.

Much well-deserved attention has been paid to the Sidewalk Widths NYC project, a digital map that “is intended to give an impression of how sidewalk widths impact the ability of pedestrians to practice social distancing.” By measuring the available width of footways, the map indicates which footways may or may not be suitable for physical distancing.
Sidewalk width provides an important piece of the “Pedestrian Supply” equation. However, it is not on its own capable of answering the central question: is physical distancing possible?
First because it is a one-dimensional measure and physical distancing is at least two-dimensional: it may be possible to keep 6 feet to the side of someone else, but is it possible to keep 6 feet in front and 6 feet behind? Given the length of many streets in New York City it may seem apparent that there is plenty of space to go around but the generously wide sidewalks of Times Square demonstrate that, under normal circumstances it is possible for these to be swamped with human activity and, as a result unsuitable for physical distancing under the new normal. Furthermore, it may be possible to observe distancing while walking mid-block but what happens at street intersections? Is there space to queue? Are the street lights synchronised to let one “platoon” of users cross before the next arrives behind them? Is flow predominantly one-directional (which it may often, but not always, be in the rush hour) or two-directional (as it can be at lunchtime)? One-way flows may have less of the “ordered chaos”, the urban ballet of two-way flows and so one-way flows may be more efficient. (more…)
















