In 1971, transportation planner John Fruin proposed a series of rules that planners would use for the next four decades as they designed urban spaces for pedestrians.
The foundation of his rules was that psychologically, people need specific amounts of space to feel comfortable on elevators, trains and other public spaces.
Early understanding of how to most effectively move pedestrians through public areas pitted two variables against each other: the density of a crowd and walking speed.
In straightforward conditions, large flows of people can predictably move quickly and efficiently. But at a certain point, the density of pedestrians becomes too great, they’re forced to move more slowly, and fewer people end up moving through the area due to the congestion.
Since Fruin’s time, figuring the ideal and specific conditions for moving people through a public space has become the work of detailed computer algorithms, even making its way into commercially available software programs.
But what’s unclear is whether these sophisticated processes are being used by today’s transit agencies and station designers, or if they’re still relying on the basic, decades-old analysis for how to move pedestrians.
What we do know is that transit station designers often rely on standards set by the Americans with Disabilities Act and evacuation guidelines set by the National Fire Protection Association to help dictate the size of platforms and other station details. These standards set minimum standards for pedestrian areas, but they don’t dictate everything about a station, nor do they outline the maximum size of a platform, for instance.
Researchers Carole Turley Voulgaris, Anastasia Loukaitou-Sideris and Brian Taylor of UCLA decided to find out whether station designers were using these modern pedestrian models in those cases where codes and standards didn’t dictate the details of a transit station. Their findings were recently published in the Journal of Public Transportation.
The Study
The researchers conducted 15 interviews with recognized experts in station design. Based on those interviews, they prepared a survey that was sent to planners, designers, managers and engineers at all 16 American transit agencies that have underground stations.
They wanted to learn everything they could about the number, type and location of elevators, escalators and stairs within the stations, as well as the dimensions of walkways and standing areas. But most importantly, they wanted to know how decisions about those elements were made. Did transit agencies rely on existing industry standards (like ADA codes), use spreadsheets based on classic pedestrian flow analysis, or take advantage of newly-available modeling software? They also asked respondents whether their strategy as they expanded was to match existing station design; correct problems they had already observed within the system; or mimic best practices the seen elsewhere.
The Findings
Transit agencies primarily rely on published standards and codes to design the size of walkways and standing areas and other elements of the station. Both classic analysis and modern, more sophisticated modeling programs are secondary when it comes to designing a transit station.
That finding itself doesn’t let the researchers determine what agencies should be doing, but it does let them draw conclusions about how well stations are designed for passenger flow.
“At present, given the generally conservative requirements of published standards and codes, most agencies do not see a need for, or an added value from, the added cost of sophisticated analysis techniques,” the researchers wrote.
The Implications
As risk-averse codes dictate the designs of transit stations, agencies should at least examine the effectiveness of those standards at moving pedestrians efficiently from time to time, the researchers say.
And since those standards will continue to dictate design standards, government agencies should look to refine the standards themselves with the analytical tools at their disposal.