Sensing the City

In the video, a human hand reaches into a tiny model intersection, pushing a Lego figure across the street as the traffic signal counts down from 10. The first time through, the Lego gets to the other side by the time the countdown is finished. Then the hand rolls the scenario again. When the Lego stops halfway through the intersection as the ten seconds expire, the traffic signal automatically adds five seconds, and the Lego makes it safely to the sidewalk.

How did the signal know what to do?

Simple: the Lego was outfitted with a sensor, made using the prototyping platform Arduino, which alerts the traffic signal that a pedestrian is in a crosswalk. If it were scaled up, the students who developed the project say, a similar sensor could be used for visually- and mobility-impaired people to make it safer for them to cross the street.

“There’s sensors absolutely everywhere, but the conversation right now around smart cities is, what could sensors do in the future?” says Assistant Professor of City and Regional Planning Allison Lassiter. This fall, for the second time, Lassiter led a class called Sensing the City, in which fifteen students from the City Planning, Masters of Urban Spatial Analytics, and Integrated Product Design programs used Arduino to develop concepts for collecting data from and interacting with the urban environment.

“Arduino is this very easy tool for prototyping digital applications,” Lassiter says. “It came out of a design school in Italy where they wanted students to be able to make interactive digital environments without being programmers or electrical engineers.”

Last week, five teams of students presented their final projects to a room of their classmates and critics, including Erick Guerra and Vincent Reina of the Department of City and Regional Planning, Ken Steif, director of the MUSA program, and Ellen Hwang, the program manager for innovation management in the City of Philadelphia’s Office of Innovation and Technology.

The class was split into three parts. For the first six weeks, students learned the nitty gritty aspects of working with Arduino. For the next three weeks, they prototyped air-quality monitors, which allowed them to test the sensitivity of the sensors and also see the limits of large-scale environmental monitoring systems. For the final leg of the semester, students split into teams of three to develop prototypes.

Two teams focused on street infrastructure. One project, described above, would adjust traffic signaling based on the presence of pedestrians in an intersection. The other, taking a cue from Philadelphia’s Vision Zero efforts to reduce traffic fatalities, would project warnings to drivers when people are near a thoroughfare on the city’s high-injury network to get them to slow down.

Another team developed a prototype that would work with the city’s Code Blue program, which helps homeless people find emergency shelter during cold weather. The proposal would outfit subway grates with weight sensors, which would automatically alert a response team when a person is resting on a subway grate for a certain length of time. Another prototype, called Platy++,  would help make subway boarding more efficient by signaling where people should distribute themselves on the subway platform. The last team developed a “smart wetland” intervention that would create floating wetlands in the Schuylkill River, which would signal when water quality is good or bad while simultaneously filtering pollutants.

All the teams earned praise from faculty critics. But the work also opened a whole set of questions: How much can sensors be relied on to improve the built environment? How could cities convince people to adopt aspects of the prototypes that require buy-in, like carrying sensors that might communicate with traffic signals? When is a technological solution cheaper and more beneficial than an analog one, like putting more resources into homeless outreach?

“A lot of [Arduino work] comes out of the art world, and it’s fun and speculative but not necessarily something that you would actually use,” Lassiter says.

Sensing the City was a chance for young planners and designers to think critically about how technology can address challenges in the built and natural environments. For Lassiter, whose research is focused on building smart and resilient cities, there are two ways to address those challenges: Low-tech interventions using the tools of landscape architecture, and high-tech experiments for evolving problems.

“I’m pretty sure,” Lassiter says, “that the systems from our past will not meet our needs in the future.”