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Fourteen streetlights along a single block in Center City have been outfitted with optical sensors as part of a pilot program to track environmental factors and how city sidewalks are being used.
Installed on 13th Street between Chestnut and Walnut, the SmartBlockPHL pilot is run by the city in collaboration with Comcast, Juganu, and U.S. Ignite — an National Science Foundation-led initiative that promotes “the smart community movement.”
The technology can detect and collect real-time data on pedestrian, vehicular, and bicycle traffic and weather conditions like air quality and humidity. The sensors were installed and calibrated last July, according to SmartCitiesPHL Director Emily Yates. Data collection began in December 2021 and will continue through the end of this year.
Initially conceived early in the pandemic, Yates said, the idea was to potentially look at streeteries, and assess in real-time whether COVID safety measures were being followed — and possibly trigger text notifications to restaurant managers if violations were detected.
As conditions changed, the team changed their goal.
“We decided that we should just keep it simple and look at things that we’re already doing,” Yates said, like assessing pedestrian or car traffic at an intersection, but “can we do that with technology, so that we don’t have to send out individuals to do manual counting.”
Without smart lights, the city sends out officials to manually collect this type of information only in specific circumstances, Yates said, like if there are complaints from the public about a specific location. The new sensors could give a sense of what’s going on at any given moment.
Other cities have tested the waters with smart streetlight technology. In some cases, it’s raised red flags among residents and privacy advocates.
In San Diego, controversy broke out in 2019 when it came to light police had been using camera footage from streetlight optical sensors in criminal investigations. The year prior, in Portland, Maine, the ACLU expressed concern about the lack of thorough public discussion around what kind of streetlight sensor data would be collected.
Local privacy law advocates stress the importance of having that discussion.
“There are so many technologies — spy planes, drones, street cameras, body cameras, individual cell phone cameras — that are used to surveil people,” said Anita Allen, a law and philosophy professor at the University of Pennsylvania, “the city needs to be extremely cautious about not going overboard with its efforts.”
The SmartCitiesPHL project tries to address. In the planning stages, Yates said, project collaborators took note of the privacy issues raised in other cities.
She stressed that none of the real-time video or audio footage of passersby will be accessible by the city or its partners. The project website says the approach prioritizes the “highest standards of civil liberties and data privacy.”
For now, the sensors are only on the 100 block of 13th Street — chosen for its abundance of transit and mix of residential and commercial uses.
After the pilot is over, the city will evaluate how useful they were and whether it’s worth installing more. The city recently wrapped up a request for proposals on the replacement of over 100,000 streetlights with LED fixtures, Yates said, and the upcoming replacements come with the opportunity to add more technology like that used in SmartBlockPHL.
“Do we want environmental sensors in each and every light pole? Were we able to take that data and turn it into a value for the city? Those kind of things,” Yates said. “The goal would be to evaluate and determine: Is it a value to the city and worth investing future dollars in?”
It’s not clear how many dollars that would involve.
The trial equipment came at no cost to the city, since it was donated by U.S. Ignite, Yates said. In general, smart street lights cost more than typical ones, but the city hopes the automation of SmartBlockPHL might result in savings elsewhere.
Balancing privacy and data collection
Here’s how it works: The sensors perform their analysis “on the edge,” Yates said, meaning that they instantly convert raw images into metadata and communicate only the presence of a human or vehicular form in a sensor’s location at a specific time.
The city can’t tell the gender or age of people on the street, she said — just the number of humans. According to the project FAQ, info transmitted looks something like this:
- Mode: Walking
- Count of people: 4
- Date: August 15, 2021
- Time: 2:26 p.m.
SmartCitiesPHL Director Yates emphasized the city is not collecting or storing any personally identifiable information.
“I don’t think we need to collect data that might be of concern to some of our community members in order to do the jobs that we want to do as a city,” Yates said. “We’re very cautious to not collect data that has PII — that’s personally identifiable information — in it.”
A concern often raised about streetlight sensors is whether they could lead to increased surveillance of marginalized communities, said Allen, the Penn privacy law expert. For instance, she said, if data collection showed a lot of foot traffic in a particular neighborhood at a certain time of day, and that led to increased police patrols as a result.
According to the SmartBlockPHL project website, the city “will not use this data to enforce laws or issue tickets.” Overall, the intention isn’t to watch people, Yates emphasized.
The term “surveillance,” Yates said, is not “part of our vernacular in this project.”
SmartCitiesPHL also has a Project Task Force, which includes external experts who review projects, ask questions, and offer feedback at various stages. The task force is advisory and does not have final approval power, Yates said.
Allen said it’s “good news” the city is looking to a panel of people they’ve determined to have relevant expertise for advice.
It’s also good that the city doesn’t intend to collect or share personally identifying information, she said, adding that it’s important for the city to accurately and transparently describe to the public how “any information or images of individuals might be collected, stored, shared, or used.”
Planning for the pilot included meeting with 13th Street stakeholders like the merchants association and civic association, providing and updating a FAQ section on the project’s website, and placing explanatory signage in the area, according to Yates.
Aggregated metadata from the pilot will eventually be shared publicly on Open Data Philly.
Anyone with comments or questions can email smartcitiesphl@phila.gov, and Yates said she plans to treat the FAQ as a “living document” that addresses questions and concerns received at that email.
“We’re collecting very minimal data points on this,” Yates said. “We’re just tracking pedestrians, bicycles, and vehicles, and then a couple environmental indicators. And the goal is to balance what the city needs versus what the technology can do.”
