Seattle knows a thing or two about dramatically changing neighborhoods. But Sant Antoni, a paper-plane shaped neighborhood in Barcelona, Spain, has seen a different kind of radical transformation.

After an extensive renovation, the art nouveau market anchoring the neighborhood returned to its original 19th-century splendor last year. In the area around it, parking was moved underground, newly planted trees and shrubs dot the streets and public plazas, children romp in new play areas, and bicyclists and pedestrians now have ample space to move around freely. In short, public space has increased by thousands of square meters — all because car traffic was deprioritized.

The urban design concept, in this case designed in tandem with local residents, businesses and others, is called a “superblock” or “superille” — and if you ask citywide City Council member Teresa Mosqueda, Seattle should get one.

Mosqueda has her eye on a 6-block area on Capitol Hill, between Pine and Union between 12th and Broadway.

“This could be a really great place to test what this model may need to be successful,” Mosqueda said. “This is an opportunity to look at what other cities like Barcelona have done to change street design elements to reduce traffic and improve pedestrian access to public spaces.”

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The superblock concept is not necessarily built on the idea of banning cars. Rather, it redirects or incentivizes car and other vehicular traffic to go around a defined group of city blocks instead of through it so that pedestrians, cyclists and residents have more space and peace of mind (and cleaner air) inside it. For the 6 blocks of Capitol Hill Mosqueda has her eye on, that could mean that car traffic with no destination in the area would be encouraged to drive on Pine, Union, 12th and Broadway rather than on the streets within the six-block area.

But, Mosqueda stressed, there is no plan yet and any push isn’t likely to come until after November’s election with seven of nine council seats up for grabs. “This is something I’d love to start exploring in 2020. This is definitely on the wish list of accomplishments before my term is up.”

An option, she said, is a short-term bill that would use temporary design elements to change the flow of traffic, which could be tested for a short period — “as soon as we feel like there has been robust community engagement.”

“I want folks to know that anything the City Council would consider, would be considered with community input, and that includes small businesses.”

The six-block area in Capitol Hill would be an ideal testing ground for several reasons, Mosqueda said. It is close to multiple transit options and a public park, Cal Anderson. Cars are already going quite slow due to traffic. And while the area’s already heavily used by pedestrians and cyclists, they are relegated to sidewalks and bike lanes with cars passing them.

“You can imagine how much safer those individuals would be if that type of through traffic wasn’t occurring there,” Mosqueda said.

Anne Vernez Moudon, Professor Emerita of Architecture, Landscape Architecture, and Urban Design and Planning at the University of Washington, also brought up safety as a key benefit of superblocks (which are not, to be clear, megablocks).

Within the confines of a superblock, “you don’t worry so much about bicycling because it’s not so dangerous. Cars don’t go very fast, or you don’t have cars. You have quieter neighborhood streets, and more of a neighborhood feel,” Moudon said, adding that within superblocks noise and air pollution levels lower and temperatures rise less.

There’s no fixed way of going about implementing superblocks. On streets within the superblock, you could reduce traffic to one lane, narrow the roadway, or limit car traffic to residents, taxi’s, police, emergency, and delivery vehicles only. Or it could be as simple as just reducing speeds, Moudon said.

“When you think of it, we already have that with the functional classification of streets,” she said, noting different speed limits on arterials and local streets. “It’s just that we don’t necessarily organize classes of streets at the neighborhood level.”

Writer David Roberts calls superblocks a “hot new urban planning idea out of Barcelona” in his five-part, in-depth series on the topic. But in a way, cities, including Seattle, have been experimenting with similar concepts for a while, Moudon said.

In 2014, Bell Street Park was branded Seattle’s version of a “woonerf,” a Dutch urban design concept (similar to a superblock) that encourages car drivers to match the speed of pedestrians in the area.

Or take “greenways,” Moudon said: residential streets with less and slower-driving cars so that people who walk or ride bicycles can feel and be safe and comfortable. She called them “the beginning of the application of super-blocking in Seattle.”

Nonprofit Seattle Neighborhood Greenways, a coalition of neighborhood groups advocating for safer streets, has also experimented with a version of superblocks called Home Zones.

“We’ve been pushing the [Home Zone] idea in areas that don’t have good sidewalks and safe places to walk,” said Clara Cantor, Community Organizer with the organization. “Particularly in North Seattle and on the edges of South Seattle.” SNG has piloted a DIY Home Zone project in the Licton Springs neighborhood. The Seattle Department of Transportation is currently running a $350,000 pilot program to create two Home Zones. Cantor said the plan is to implement one in South Park, and one in the North End.

What would leave Seattle’s efforts trying to catch up with Barcelona and other European cities, however, is that there, similar efforts go hand in hand with larger-scale projects pedestrianizing city cores and/or partly banning cars to cut air and noise pollution and reduce greenhouse gas emissions.

In Seattle, a superblock would only be a drop in the ocean, Moudon suggested. The only way Seattle can solve the pollution puzzle (and benefit the environment and people’s health) is by reducing the number of cars overall, she said.

“If we don’t reduce the number of cars, but we do make superblocks, what will happen is that along the superblock’s higher-speed streets, you will have more noise, more air pollution.”

Still, the health benefits — less noise and air pollution, more exercise — within a superblock are clear, Moudon said, and there are other benefits as well: In Barcelona’s superblocks, foot and bicycle traffic has increased, as has commercial activity.

“In other cities, there was some protest from business owners who said they’d lose revenue, but the opposite has happened,” according to studies, Moudon noted.

“If you are in a car, you are not going to stop for coffee easily, but if you’re walking around, you’ll say, mm, a little donut, a little coffee. It’s very well known that in denser places, if people are walking more, they (…) buy more things.”

Mosqueda echoed the sentiment. “In Barcelona (…) what they saw was an increase in overall sales for small businesses and an increase in foot traffic. And that is true of what we’ve seen when we’ve gotten rid of parking spots and reduced traffic and lanes in front of small businesses across our own country,” she said.

“So I think it’s a win, win, win: a win for local business, a win for safety of pedestrians and bicyclists, and a win for the environment.”