Episode 15: Flexible Streets

What if we could use design and technology to make our streets more flexible? So they could change use according to the season, the week — even the hour?

Cyclists riding along a sidewalk
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“City of the Future” is a podcast that explores ideas and innovations that could transform cities. In this episode, hosts Eric Jaffe and Vanessa Quirk talk about the potential of flexible, responsive streets with former New York City Department of Transportation Commissioner Sam Schwartz, Aspen Director of Parking & Downtown Services Mitch Osur, and Coord Head of Policy & Partnerships Dawn Miller, as well as Sidewalk Labs Senior Creative Technologist Nick Jonas, Associate Director of Planning & Delivery Siqi Zhu, and Director of Mobility Willa Ng.

Sam Schwartz: The streets say something about who we are. And New York streets should say, number one: we walk. Number two: we take transit, and we bike, and we eat, and we enjoy, and we like music and all the other things. We dance in the streets.

Vanessa Quirk: That’s Sam Schwartz, a lifelong New Yorker and transit guru who’s known around these parts as Gridlock Sam.

Sam Schwartz: The word gridlock came about during the 1980 transit strike, at least publicly, I was an assistant Department of Transportation Commissioner at the time. So I put this thing called grid lock, two words, grid lock prevention plan. And when city hall saw that, they said, we don’t know what gridlock is. Let’s get the guy who knows what it is to prevent it. And so gridlock has been associated with me ever since. I released it to the lexicon.

Eric Jaffe: We had a socially distanced, fully masked meet-up with Sam over the summer to take a look at how New York City streets were opening up to people — not just cars — in response to COVID-19.

Sam Schwartz: City street space, which was totally for cars, can be used for sitting areas, for dining areas, for bikeways.

Vanessa Quirk: Even though Sam was really excited about these new Open Streets, when we happened across one on the Upper West Side, he found its design was…lacking.

Sam Schwartz: Here is a street that’s closed with a wooden sawhorse. These sawhorses were old when I started 50 years ago, and you can’t completely trust the cars. There’s a car going right through. Right around.

Vanessa Quirk: So the sign says, “Share the road. Do not enter except local traffic. Five miles per hour.”

Sam Schwartz: Alright, so that guy is not local, he’s continuing, he’s going through the next block. Pedestrians be damned, dog walkers be damned. Barely slowing down, and there could be children playing, there could be somebody darting out. That person is not going five miles an hour, he’s doing about 15 on it.

Eric Jaffe: Just to get to a red light.

Sam Schwartz: And going through the red light.

Eric Jaffe: We’re handing out tickets left and right here.

Vanessa Quirk: Our imaginary tickets.

Sam Schwartz: Those were the good days when I was doing it.

Vanessa Quirk: Even though Sam wanted to give a lot of tickets to this particular driver, he insists that he’s not about taking away streets from cars completely.

Sam Schwartz: I’m not anti-car. I want to see balanced transportation. I also want to see cars in urban areas go very slowly. Nowadays we’re killing pedestrians at an alarming rate. So we need a balance. The cars have to go slower. And how do the cars go slower? Not by just putting up speed limit signs, that doesn’t do it because you don’t have a cop everywhere, you don’t have a camera everywhere. You need to do it through design.

Eric Jaffe: As we walked through the streets of the Upper West Side, Sam saw examples of the power of good design everywhere.

Sam Schwartz: Take a look over here!

Vanessa Quirk: Sam walked us towards a crosswalk, where the sidewalk had kind of been extended out, and the space for the car had been narrowed.

Sam Schwartz: So this is called a neckdown, and this was done circa 1971 when I started with the traffic department. So this was about 50 years old. It’s the first attempt at trying to tame a street through design. And you could see that traffic has to go more slowly, nobody can go around them as they go through. The pedestrian has only about 15 feet to cross as opposed to 30 feet to cross, so the pedestrian’s exposure it’s a lot less over here. Here we see a father with a child in the stroller and within four seconds he’d cross the street, as opposed to eight seconds. Four extra seconds — multiply it by 8 million people crossing and you increase the probability of crashes.

Vanessa Quirk: If Sam were in charge again, he has some ideas for how he’d transform the streets of today into the safer, more flexible, more responsive streets of the future.

Sam Schwartz: We should use our streets in a smart way temporally. We should think of the street of the future as one that does change during the day, during the day of the week, during the season, and we should use some technology and human power combined to make it happen. We can do almost anything, technologically. These are the 2020s.

Vanessa Quirk: Welcome to City of the Future, a podcast from Sidewalk Labs.

Eric Jaffe: Each episode, we explore ideas and innovations that could transform our cities.

Vanessa Quirk: We’re your hosts. I’m Vanessa Quirk.

Eric Jaffe: And I’m Eric Jaffe.

Vanessa Quirk: And in this episode we’re talking about an idea that could allow one of our most precious public spaces to serve the needs of everyone.

Eric Jaffe: Flexible streets.


Vanessa Quirk: So how can we get closer to that vision of more flexible, responsive streets?

Eric Jaffe: Well, according to Gridlock Sam, the first step is data.

Vanessa Quirk: Throughout his storied career, Sam has gotten into a lot of political battles over streets. And data has given him the leverage he’s needed to turn plans into realities.

Eric Jaffe: For example, Sam told us about a controversial effort in the 1970s to re-evaluate the number of lanes open to cars in Central Park.

NYC and Central Park viewed from overhead

Data collection has been critical to improving street designs in places like New York City’s Central Park.
(Image: Jermaine Ee / Unsplash)

Vanessa Quirk: The first thing Sam and his colleagues did was hang out in the park counting cars. But the technology they used was rudimentary.

Sam Schwartz: Traffic counts in the 1970s were largely done by pneumatic tubes. And every time there was an impact, every two impacts would be one car. How accurate was it? Within 10–20%. It wasn’t particularly that accurate. And then sometimes, people in communities who wanted red lights or traffic signals, they would jump on it to make the counts show up.

Eric Jaffe: Since pneumatic tubes weren’t always reliable, a lot of the data collection for that Central Park study had to be done by hand.

Sam Schwartz: Somebody stood out with a clipboard and we have these counters and it has like five or six buttons depending. And it’ll say left turn, right turn, straight through. So we looked at the data and what we found was, very easily, we could take the three lanes and make them two lanes. And it’s really the first time lanes were taken away from cars since the turn of the century.

Vanessa Quirk: Sam was only able to make this real, meaningful change because of the data! And today, data is more important than ever.


Mitch Osur: Five years ago when it came to parking, it was all about the equipment, the equipment, the equipment. Well, in the last three to four years, we’ve seen a drastic change to data, data, data.

Eric Jaffe: Mitch Osur is the Director of Parking and Downtown Services for the city of Aspen, Colorado.

Vanessa Quirk: Like Sam, Mitch has had his fair share of battles over street space. And he’s seen the power of data to change people’s minds.

Eric Jaffe: For example, four years ago, he decided to double the parking prices in the downtown core. Businesses were outraged. They worried that customers would be scared away and sales would plummet.

Mitch Osur: I told them all, “Give me three months. At the end of three months, you’re either going to kiss me or you’re going to want to punch me, one or the other.” They all called me three months in and said, “We can’t believe it, but your plan actually worked.”

Vanessa Quirk: While locals were deterred by the new prices, visiting shoppers weren’t — and they now had even more access to the shops.

Mitch Osur: We had a 17% increase in sales tax revenue for that three-month test.

Eric Jaffe: So nobody punched you.

Mitch Osur: No, they actually wanted to kiss me because it worked so well.

Eric Jaffe: Mitch is always thinking about how to test out solutions that could make Aspen’s streets better for shoppers, restaurants, pedestrians, and visitors.

Vanessa Quirk: And the biggest obstacle currently facing the city is trucks, which every day dangerously clutter up the downtown’s limited curb space.

Mitch Osur: Our problems are really driven by FedEx and UPS and all the other truckers coming to town. On a busy day, these trucks are double parking, maybe even triple parking, and that’s not safe for anybody.

Eric Jaffe: To help figure out a solution to this curb congestion, Mitch and the City of Aspen teamed up with Coord, a Sidewalk Labs incubated company.

Dawn Miller: Coord is an online platform to help cities manage their curb space.

Vanessa Quirk: That’s Dawn Miller, Head of Policy and Partnerships at Coord, which has developed an app for commercial drivers that lets them see the location and availability of parking or loading zones.

Dawn Miller: They can see one that’s available near where they want to go, they can put a hold on it, and when they get there, they book in and pay for the space. This way they have really a greater incentive and information to go to those safe and legal loading spaces rather than falling into some old habits of doing things like blocking crosswalks or double parking.

Eric Jaffe: The app doesn’t just benefit drivers. It helps cities get more information about what’s happening at their curbs.

Mitch Osur: I want to know the length of stay. How long are these trucks staying? Are they staying for 15 minutes or are they staying for two hours? What time of day are they coming? We’re really excited to learn how this works so we can make decisions on how our loading zones should be moving forward.

Vanessa Quirk: This information could give Aspen some ideas for pilots — so they can figure out what policy decisions might be best for the city.

Eric Jaffe: And the less expensive the pilot, the better.

Mitch Osur: I’m a big believer in experimenting before you either spend a lot of money or do something else, so let’s do it inexpensively, give it a shot. You’ll know within 90 days whether it works or not, then you go ahead the next year and put it in. That’s the position we’re in.

Vanessa Quirk: Due to COVID, Dawn is seeing that cities are much more open to these kinds of experimentations — and not just for their curbs, but their entire streets.

Dawn Miller: What I think we’ve all seen out of COVID times is that they’ve opened up people’s imaginations that a street doesn’t have to be parallel parking or angled parking on each side. They can be a lot more. And I think a lot of the transportation community has wanted to do a lot of different things for a long time, but it was politically very difficult to get people to accept new ideas. Hopefully, a lot of cities are like Aspen where they want to keep some of these new things and then going forward makes them more open to trying different things because we tried something in an emergency and it actually was really cool.

Mitch Osur: I’ll second what Dawn just said. I think that in Aspen in particular, the COVID experience has really opened people’s eyes. Just this winter, we’re thinking about actually grooming some of the streets so that people can cross-country ski on some of the roads around town, things that last year never would have even been part of a conversation.

Vanessa Quirk: Ski lanes — that sounds like an amazing way to use the streets in Aspen!

Eric Jaffe: I love it. It’s not that easy, though, for every city to do pilots like this. Aspen has access to affordable data collection technology through their partnership with Coord, but in general it can be really expensive for cities to collect accurate street data.

Vanessa Quirk: It’s certainly a pain point, which is why some of the folks at Sidewalk have been working on a solution.


Nick Jonas: My name’s Nick Jonas. I’m a Creative Technologist at Sidewalk Labs.

Vanessa Quirk: Cool. I hate to ask this question, Nick: you are not the Nick Jonas of Nick Jonas fame?

Nick Jonas: Oh, yeah. I can clarify I am not that one. I’m not in a boy band.

Vanessa Quirk: Nick is part of a band of folks who have been working on a new vehicle occupancy sensor. They call it Pebble.

Nick Jonas: It’s basically a magnetometer and an optical infrared sensor that basically detects a shift in the magnetic fields as a car drives over it.

Vanessa Quirk: Right. I don’t know what a magnetometer or an infrared thing looks like. But to me, it just looks like a piece of plastic.

Nick Jonas: It’s a piece of plastic. Some people will call it a puck.

Vanessa Quirk: Yeah, like a hockey puck.

Nick Jonas: It’s a round, plastic housing for the sensor.

Vanessa Quirk: If I put my hand over it and wave it around, I’m disrupting its infrared light stuff?

Nick Jonas: Not quite. The way it works is it needs a big piece of metal, like a car, to disrupt the magnetic field.

Vanessa Quirk: Nick explained that it’s the magnetometer that turns on the higher-powered infrared optical sensor, which is what let’s the app know that something’s there. So because I am not made of metal, I don’t disrupt the magnetic field and hence don’t trigger the sensor.

Eric Jaffe: Right. And so I’m guessing that if Pebble can only detect whether or not a vehicle is present — that means it can’t pick up any identifiable information, right?

Vanessa Quirk: Yeah, it was designed with privacy in mind. But the main selling point for Pebble is that they’re affordable. And a big part of that is how easy they are to install. What used to require construction crews opening up the streets is now easy enough for Nick and I to do in just a couple of minutes.

Nick Jonas: I am just peeling off the plastic of this goopy — basically a sticker that we’ll use, just stick it to the ground. And then, you just step on it to apply some pressure. There you go. Now it’s not going anywhere. You’ll see in the app.

Vanessa Quirk: Oh, there it is.

Nick Jonas: It is healthy and connected.

Vanessa Quirk: Welcome to the world, little Pebble!

Nick Jonas: So, no cars over it. You should also be able to see its occupancy state. And it’s showing available.

Vanessa Quirk: Oh, yeah.

Nick Jonas: That was quick.

Vanessa Quirk: That took a couple minutes. But we weren’t there just to install Pebbles. Nick Jonas had some testing to do.

Nick Jonas: We actually haven’t tested with a motorcycle, so that’s why I’m here today.

Vanessa Quirk: You’re hearing it here, folks. For the first time ever, we will see if the Pebble detects a motorbike.

Motorcycle sound.

Vanessa Quirk: Okay. Something’s happening on the screen. It is gray. It is occupied.

Nick Jonas: Oh, nice. Alright, great.

Vanessa Quirk: Motorbike detected. Good job, little Pebble!

Eric Jaffe: I’m super jealous you got to see the Pebbles in action.

Vanessa Quirk: You should be, Eric. Pebbles are just one way that cities could get data affordably, which can help them allocate street space for the right use at the right time.

Eric Jaffe: And there’s the potential for more than that too. You can imagine cities using that data to help people get around. They could tell my smartphone, “Hey, there’s a parking spot over there, and if you want to park there, it’s going to cost this much right now.”

Vanessa Quirk: Or it could tell you, “This street is actually closed right now, because curbside dining has been expanded into the street, so you should take another route.

Eric Jaffe: Right, there’s a lot that can happen in terms of communication once you have that digital layer in place, which you need if you want to make streets truly flexible, right? The more you want to share the street, between cars and people and shops and any other use, the more that communication piece becomes key. Otherwise things get chaotic, even dangerous.

Vanessa Quirk: Totally, which is why it’s important to think about how we can communicate information using the street itself. Right now, we can put up signs, sawhorses, or maybe paint — which can do a lot, but it’s not enough if you potentially want a street to change uses multiple times in one day.

Eric Jaffe: That’s actually something other folks at Sidewalk have been thinking about for quite some time. Things like digital signs that can convey new rules of a street much more dynamically. Or, as you’ll remember from Season 1, the idea that lighted pavement could indicate a specific use.

Vanessa Quirk: Actually, the Streets team at Sidewalk have been working on a pilot project, a Street Lab, to bring these ideas to life.


Siqi Zhu: So, in addition to the LED pavement and the digital signage, we also have vehicle presence detection sensors embedded in the pavement.

Vanessa Quirk: Those are going to be the Pebbles.

Siqi Zhu: The Pebbles, yes.

Vanessa Quirk: I know about those because I tested them out with Nick Jonas on a motorcycle.

Siqi Zhu: Very cool.

Vanessa Quirk: That’s Siqi Zhu, Associate Director of Planning and Delivery at Sidewalk, and he met me at an industrial zone in Brooklyn, where the Street Lab is currently under construction. It didn’t look like much — just a few hundred square feet alongside a sidewalk next to a brewery — but Siqi showed me what to look out for. Like the small bumps along the edges that would help people with visual impairments navigate. The places where digital signage would soon go. And even a mock-up that showed how they were going to glue the LED lights down onto the street surface. With all these innovations working together, Siqi thinks a lot could be possible.

Vanessa Quirk: And Eric, I’m going to take you through them. I’m going to take you through a day in the near future of the Street Lab. Are you ready?

Eric Jaffe: I can’t wait. I’m ready for this future!

Vanessa Quirk: Let’s go. So it’s 9 a.m. sometime in Spring 2021. It’s a beautiful, hypothetical day. You’re standing on this street corner, and there are LED lights flashing red under your feet. And a digital sign would be there too, saying “No Parking!”

Eric Jaffe: Got it. Not going to park.

Vanessa Quirk: But, Siqi did say that dropoff and pickup would be okay, because that allows for a lot of people who are coming for work to get dropped off efficiently.

Eric Jaffe: After rush hour has ended, and everyone’s gotten to work, I’d imagine the sign changes.

Vanessa Quirk: Right, the lights under your feet would turn green, and the sign would say, “Come on over, you can park here.”

Eric Jaffe: At least until the end of the day, maybe 5 p.m., when you probably need that pickup and dropoff zone again.

Vanessa Quirk: Exactly.

Eric Jaffe: Alright, so what’s after that?

Vanessa Quirk: Siqi and the team are actually imagining something pretty fun.

Siqi Zhu: In the evenings, after peak pickup and dropoff have occurred, we imagine making the space available for adjacent businesses to take over as outdoor seating and dining space. Vanessa Quirk: Right, because I see this brewery right here has tables and chairs out already on the sidewalk. So you could imagine once this extends out and the signage says, “Hey, no parking here right now or for the next few hours,” and the lights are like, “No parking here,” then this could become more outdoor dining space.

Siqi Zhu: Yep, exactly.

Eric Jaffe: It sounds great, but it also sounds like a lot to ask of cities. I mean, this is a bigger infrastructural lift than just sticking down a Pebble, right? Will cities make that shift?

Vanessa Quirk: I think they will. Think about what we’ve learned in our conversations with Sam and Mitch and Dawn. Because of COVID, cities and streets are already shifting in this direction.


Willa Ng: This place looks really different.

Vanessa Quirk: How so?

Willa Ng: I see people walking down the middle of the street without having cars behind them honking their horn. That’s unusual for Doyers Street.

Eric Jaffe: That’s fan-favorite Sidewalker Willa Ng. You might remember her from Season 1, Episode 3, on adaptive traffic lights.

Vanessa Quirk: Of course you remember Willa. We donned our masks and met up with her in New York City’s Chinatown, where she grew up. And Willa was astonished by the recent changes in her old neighborhood.

Willa Ng: I’ve got people who are just sitting at tables in the middle of the roadway. This is great.

Eric Jaffe: Restaurants had set up dining platforms where the street parking used to be. Cars were still passing through, but they were actually abiding by the 5 mph speed limit.

Willa Ng: When vehicles are traveling at 5 mph, which is the speed that someone can walk briskly or jog, that vehicle is no longer threatening. And I think you can kind of see that that’s happening right now. So I think that this kind of proves that case that I’ve always posited that your business can thrive without people being able to drive directly to your front door. What we need is more outdoor space for dining, we need more people walking to our location. I hope that that’s what sticks in the mind of these business owners. You know historically the Chinese restaurant owners have been resistant to getting rid of parking.

Vanessa Quirk: Oh yeah. If we had said this a year ago that this was going to be happening here on the street, we would be like no way, never going to happen. And yet, here we are.

Eric Jaffe: Does it feel like you would’ve wanted it to feel?

Willa Ng: No, it doesn’t exactly. I think I wanted there to be a bit more porousness between the pedestrian and the café seating zone and the vehicular zones.

Eric Jaffe: What do you mean by that?

Willa Ng: There’s generally still this, “This part is mine, that part is yours.” And I can see why that needs to be the case right now, but I feel like if people got used to it, you could actually get rid of these barriers and have much more of an undefined line between where the pedestrians are and the cars are.

Eric Jaffe: So Willa is basically describing the idea behind the Street Lab here.

Vanessa Quirk: Yeah. Like Siqi told me, the whole goal of the lights, the digital signs, and the pieces of the Street Lab, is just to make streets like these feel comfortable for everybody, so they can feel like they really belong to everyone.

Siqi Zhu: We can really reset the balance between the pedestrian and vehicular nature of the street with a system like this, and that’s the aspiration. I do think this flexibility opens up the possibilities for sharing the space more equitably.

Eric Jaffe: This moment is clearly an opportunity to get to that vision of a more equitably shared street. But a lot will have to happen before we can get there.

Vanessa Quirk: We need street design that encourages drivers to slow down and share the road. We need sensors so we understand what’s happening at the street level — who needs what, when. We need some sort of digital layer to help cities make sense of that data, and make decisions and rules. And then we need some physical infrastructure, so the street itself can interface with people and let them know a street is for parking right now, or unloading trucks, or eating, or dancing, or skiing, or whatever!

Eric Jaffe: It’s definitely a lot. But it’s also exactly what cities need to be working toward.

Vanessa Quirk: And actually, Eric, there is one more thing. It’s probably the most important one. As our colleague Willa likes to point out, what we really need is to come together and agree that a shared street is what we want for the future of our cities.

Willa Ng: I think that we have to agree to the premise that the street is to be shared first. I think that that’s the number one battle. To say we have this amount of concrete and asphalt, and instead of it being segregated into, “Here’s where the pedestrians are, here’s where the cars are, here’s where the parking is,” that we’re much more fluid with all of it, and that we should be allocating space to whoever needs it the most at the time. Then allocate that space fairly, and not just to whoever has the loudest voice.


Eric Jaffe: Thank you for listening to City of the Future, a podcast from Sidewalk Labs. Your hosts are Vanessa Quirk and me, Eric Jaffe. We’re produced by Benjamen Walker and Andrew Callaway.

Vanessa Quirk: Mix by Zach McNees. Our music is composed by Adaam James Levin-Areddy. If you want to hear more of his work, check out his band, Lost Amsterdam. Special thanks for this episode goes to Sam Schwartz, Mitch Osur, Dawn Miller, Nick Jonas, Siqi Zhu, and Willa Ng.

Eric Jaffe: This was our season finale, so you won’t be hearing from us for a while. But you can keep up with Vanessa and me through the Sidewalk Labs newsletter, or you can send us a note by emailing We always love to get listener feedback and suggestions. And if you like the show, then please rate us on Apple or wherever you listen to podcasts. It really helps.

Vanessa Quirk: And as this is the season finale, I’d also like to give a shoutout to Daniel He, Maggie Zhang, and Moto Okomura, who have helped the great Tim Kau create the art and social content for this season. And if you’re not following us on Instagram already, you can see all the great content that they have created by visiting @cityofthefuturepod.

Eric Jaffe: That’s it for this season. See you in the future!

Vanessa Quirk: Bye.