Plazas and Other Spaces

A sunny Sunday afternoon in April looking out over San Francisco's Dolores Park with the city skyline in the distance.
Well over a thousand people were enjoying the sun that day, H Graem © 2007

The New Oxford American Dictionary defines a plaza as, "a public square, marketplace, or similar open space in a built-up area". It defines a square as, "an open area surrounded by buildings in a town, village or city" or "an open area at the meeting of streets."  Wiktionary calls a plaza, "A town's public square." or "An open area used for gathering in a city, often having small trees and sitting benches."

These definitions are pretty much interchangeable. Although the names differ, the spaces so variously titled are similar. Jointly they describe a public open space dedicated to social activity of the city. Such spaces will continue to exist in the future city as they have for millennia in the past.

 

Criteria for Success

Pedestrians entering the Plaza Grande in Quito, Ecuador.
H Graem © 2007

More important than what a public space is called is its actual success as a public space enjoyed by the people in the city. Many cities have attempted to create such spaces to bring people together. Not all have succeeded as a public gathering place. Too many are notorious for their emptiness rather than famous as a vibrant gathering place.

This post is searching for commonality among successful urban open spaces. What have urban theorists and users of urban spaces discovered on the subject? What attributes have been found to lead to success?

Characteristics have been discovered which appear to lead to such success. I will call such characteristics; attributes of successful urban spaces. My sources are three urban theorists (Jane Jacobs, Camillo Sitte, and Christopher Alexander) and the Project for Public Spaces. The following attributes are culled from these four sources.

Attributes* of Successful Urban Spaces

 

Kites in smog shrouded Tiananmen Square, Beijing, China
H Graem © 2007

Enclosure - Give outdoor spaces some degree of enclosure; surround each space with wings of buildings, trees, hedges, fences, arcades, and trellised walks, until it becomes an entity with a positive quality and does not spill out indefinitely around corners [CA: 522]. Although buildings should not cut sun from a park - if the object is to encourage full use - the presence of buildings around a park is important in design. They enclose it [JJ, 138]. Public squares should be enclosed entities. The main requirement for a plaza, as for a room, is the enclosed character of its space [CS, 170].

Diversity - Possesses a diverse rim and diverse neighborhood hinterland... Only diverse [economic and social] surroundings have the practical power of inducing a natural, continuing flow of life and use [JJ: 125, 132]. The streets and sidewalks around a square greatly affect its accessibility and use, as do the buildings that surround it. An active, welcoming outer square is essential to the well-being of the inner square [PPS: 7].

Quiet time in December on the 'Esplanade' of Yerba Buena Gardens
H Graem © 2007

Intricacy - Intricacy at eye level, change in the rise of ground, groupings of trees, openings leading to various focal points - in short, subtle expressions of difference [JJ: 136]. Any great square has a variety of smaller "places" within it to appeal to various people [PPS: 2].

Sun - Sun is part of a park's setting for people, shaded, to be sure, in summer [JJ: 138].

Clear Centers - That the center of plazas be kept free. To the ancient rule of placing monuments [and buildings] around the edge of public squares is thus allied another ... to place monuments and ... fountains at points in the square untouched by [vehicle] traffic [CS: 162, 163].

Map of Yerba Buena Gardens with its Esplanade
at the center and the Children's Garden below
next to the Moscone Convention Center.

Size - A good proportion between the size of a plaza and that of its buildings is of primary importance. [A plaza] that is too large is ... awkward because even the mightiest of structures seems dwarfed in relation to it [CS: 177+]. Make a public square much smaller than you would at first imagine; usually no more than 45 to 60 feet across, never more than 70 feet across. This applies only to its width in the short direction. In the long direction it can certainly be longer [CA: 313].

Irregularity in Shape - Irregularities [of old plazas] do not have an unpleasant effect at all, but on the contrary, they enhance naturalness, they stimulate our interest, and, above all, they augment the picturesque quality of the tableau [CS: 186].

Flexibility - The use of a square changes during the course of the day, week, and year. To respond to these natural fluctuations, flexibility needs to be built in. Skating rinks, outdoor cafés, markets, horticulture displays, art and sculpture help adapt our use of the space from one season to the next. Great squares ... change with the seasons. [PPS: 4 & 5].

Access - A square needs to be easy to get to. The best squares are always easily accessible by foot. Just as important as the edge of a square is the way that streets, sidewalks and ground floors of adjacent buildings lead into it. Elements within the square are visible from a distance, and the ground floor activity of buildings entices pedestrians to move toward the square. A square surrounded by lanes of fast-moving traffic will be cut off from pedestrians and deprived of its most essential element: people. [PPS: 6 & 8].

*The attributes come from four sources. The particular source is indicated by the author's abbreviation and the page number, or in the case of the PPS, the Principle number.

• Alexander, Christopher, et al, A Pattern Language, 1977.
• Jacobs, Jane, The Death and Life of Great American Cities, 1961.
• Sitte, Camillo, City Planning According to Artistic Principals, Dover, 1986 (Original in German, 1889, Translated by George R. Collins & Christiani Crasemann Collins).
• The Project for Public Spaces, based on analysis of successful urban spaces, has created 10 Principles for Successful Squares. 

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The Esplanade and the Children's Garden of Yerba Buena Gardens in San Francisco well illustrate the attributes discussed here. Of the nine attributes, only Alexander's size standard appears violated, or in this case, exceeded. Even better, Yerba Buena Gardens masks one of the most aesthetically destructive urban edifices, the Muscone convention center. The city wisely located much of this facility underground.

In contrast, Tiananmen Square appears to violate most of the attributes. It is one of the largest squares in the world. Its vitality is saved by its location at the center of China's capital city adjacent to the Forbidden City of the former emperers. Without the people drawn within by the adjacent uses, it would be a most forbidding (pun intended) place.

Washington Square                                                                           Union Square  
(Street and Satellite Views: © H Graem © Google Maps)

Washington Square is one of the top squares in the United States and Canada according to the Project for Public Places. Union Square was one of Jane Jacobs' favorites, although she referred to a previous version. As she said in her book, Union Square in downtown San Francisco has a plan that looks deadly dull on paper or from a high building; but it is bent into such changes in ground level, like Dali's painting of the wet watches, that it appears remarkably various. The changes in ground level still remain.

Park in the Sky

 

With the finishing touches going on in 2019, San Francisco now hosts what might be the largest and most unique public park in the world. Salesforce Park is the roof of the Transbay Transit Center designed to centralize the San Francisco Bay Region’s transportation network by conveniently connecting all points in the “Grand Central Station of the West”.

Salesforce Park as seen from a satellite view in Google maps.

The 5.4 acre Salesforce Park (the company purchased the naming rights) on top of the Transit Center extends 1,430 feet (440 m) long and 165 feet (50 m) in width with a park surface some 70 feet in the air. Salesforce Tower, next to the transit center at First and Mission streets, has a fifth-floor bridge leading to the rooftop park.

Salesforce Park walking trail
H Graem © 2019

The park satisfies almost all of the "Attributes of Successful Urban Spaces" discussed above, albeit sometimes in rather unique ways. The park was comfortably used by adults and children when I first visited in the summer of 2019.

Salesforce Park escalator access
H Graem © 2019

The public is welcome to enjoy this public park during daylight and early evening hours. It can be reached by elevator, escalator, bridges from two towers and a 20 passenger glass gondola car. A living roof with a curved walking trail for running/walking and lined with benches surrounds open grass areas for picnics, lily ponds, dancing fountains, a children’s play area, and an amphitheater for staging free events. Designed to house more than six native plant communities, the green roof features bodies of water, statuesque trees and is dedicated to sustainability. The park is home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas.

The park is a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a children’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®. Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.

• Everyone’s welcome to enjoy this public park, a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a children’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®.
  
• Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 different botanical feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.
  

• Everyone’s welcome to enjoy this public park, a living roof where a curved walking trail lined with benches surrounds grassy lawns, dancing fountains, a’s play area, and an amphitheater for staging free events from arts and crafts to Zumba®.
  
• Seventy feet above the Grand Hall, the Park runs the entire length of the Transit Center’s nearly four-block stretch. Home to 600 trees and 16,000 plants arranged in 13 differe feature areas, the newest public park in the San Francisco Bay Area is for the benefit and enjoyment of all...and there’s nothing else like it anywhere.
  

Correcting Mistakes

In recent decades there has been an active effort worldwide to remove elevated highways. Many such highways, constructed in the middle of the 20th century to speed traffic, are now seen as obstacles to vibrant urban development.

Tom McCall Park in Portland, Oregon

From Korea to the United Statesa, there has been a new awareness of unintended consequences related to these expensive and massive highway structures designed to overcome traffic congestion. They  were found to be a medicine more devastating than the congestion disease. Progress in correcting this mistake has been slow but steady since Portland, Oregon removed its riverside freeway and replaced it with a park in 1972.

Korea

In Seoul, Korea, a former river was placed underground when an elevated highway was completed in 1976.  Restoration starting in 1973 returned the river to a more natural state and removed most of the highway lanes. Mayor Lee of Seoul who was responsible for the elevated highway removal and the creation of a riverside park upon the former highway site, was elected Korea's president in December 2007.

Cheonggyecheon River restoration project

 

Seattle

Future Seattle waterfront envisioned by 2023

Progress on the most recent elevated highway removal is occurring in Seattle, WA with the replacement of the Alaska Way Viaduct.

In the Fall of 2011, Seattle's Alaskan Way Viaduct began to crumble. City planners and downtown businesses hoped the removal of the elevated structure would be the catalyst for a whole new waterfront with a broad pedestrian way and a seaside promenade. In November 2012 voters approved by 77 percent a $290 million bond measure to pay for replacement of the most eroded and threatened section of the sea wall — a linchpin of the waterfront renewal package. 

After numerous interruptions, a Viaduct replacement tunnel constructed using the Big Bertha tunneling machine was completed.  Traffic is now rolling through the new underground way. 

Final demolition of the former Alaska Viaduct is now underway. Progress on one segment can be viewed on this video of demolition in May 2019. 

The two images envision scenes on the future waterfront after implementation of the plan. Waterfront construction is anticipated to be completed in summer 2023. Seattle Magazine provided an overview early in 2019 of the future expected Bold New Waterfront experience.

San Francisco

The San Francisco waterfront was blocked off after the Embarcadero Freeway was constructed in the late 1950s. There was a dreary darkness associated with the spaces beneath and the buildings under the shadow of this massive structure. If it wasn't for the San Francisco citizen revolt that followed its construction, the freeway would have eventually walled off the waterfront as far as the Golden Gate. As it was, it extended more than half a kilometer north of the Ferry Building before it turned inland upon its final off ramps.

Art Agnos, Former San Francisco Mayor

The 1989 Loma Prieta earthquake damaged the structure. At first the State of California planned to retrofit and retain the two-decker freeway. Then Mayor Art Agnos proposed demolishing the freeway in favor of a boulevard with a large plaza in front of the Ferry Building.

Opposition to demolishing the freeway came from Chinatown and the city's downtown businesses. Agnos continued to negotiate with federal and state officials to win enough funding to make the demolition practical. The opposition quieted. Demolition began in 1991.

The city and its downtown and Chinatown businesses survived quite nicely with the renovated Embarcadero. In the image below we see the Embarcadero no longer shadowed by the elevated behemoth. The Ferry Building insert shows how it was previously walled off by the elevated, double-deck highway.

The view looks north along the Embarcadero toward the Ferry Building. The inset is an aerial view of the Ferry Building when the Embarcadero Freeway still existed. H Graem © 2007

June 16, 2006, the Port of San Francisco unveiled a monument to Mayor Agnos honoring his vision and courage, noting "This pedestrian pier commemorates the achievement of Mayor Agnos in leaving our city better and stronger than he found it."

Jane Jacobs (1916-2006)

Through her book, The Death and Life of Great American Cities, Jane Jacobs opened the eyes of many planners (including myself) to the reality of what made for city success or failure as a human environment. In effect she said the 'radiant' city approach espoused by Le Corbusier, and so popular with planning professionals at the time, had no basis in reality - 'the emperor had no clothes'.

She presented a readable and thorough analysis of cities as people actually experience them. One of her most recognized observations was the importance of 'eyes on the street' for cities to succeed as human environments. The examples that follow are just a few of the observations set forth in her book and communicated throughout her lifetime and beyond.

North Beach District of San Francisco
H Graem © 2012

 

City Districts

For the districts or communities of a city to succeed as places of "exuberant diversity", four conditions are seen as indispensible:

(1) The district serve more than one primary function (preferable more than two). These functions must assure the presence of people outdoors on different schedules, for different purposes, but able to use many facilities in common.

(2) Most blocks must be small, with frequent opportunities to turn corners.

(3) The district must include buildings that mingle the old and the new, including a significant proportion of old ones that vary the economic yield necessary for profitable operation. The mingling must be close-grained.

(4) There be a sufficient dense concentration of people, including both residents and workers.

Jane states, "The necessity for these four conditions is the most important point this book has to make." She cited the North Beach / Telegraph Hill district of San Francisco as an example of such exuberant diversity.

Streets

Morning exercise in Shanghai, China
H Graem © 2007

A well-used street characterized as a safe city asset must have three main qualities:

(1) A clear demarcation between what is public space and what is private space. These spaces should not ooze into each other as they tend to do in suburban settings and low income housing projects.

(2) There must be eyes upon the street. The buildings - to assure the safety of both residents and strangers - must be oriented to the street. There should be no backs or blank sides along it.

(3) The sidewalk must have users fairly continuously. These users would add to the effective eyes on the street and induce the people in the buildings along the street to watch the sidewalks in sufficient numbers. Nobody enjoys looking out a window to an empty street.

 

Parks

Successful parks are in nurturing diversified neighborhoods capable of using and supporting parks. This means genuine economic and social diversity with people on different schedules free to use the park at different times.

The park itself should be characterized by intricacy at eye level - a change in height, tree groupings, openings to different focal points - which result in differences in use across the park.

Other keys to a successful neighborhood park include (1) a center, main crossroad and pausing point, a climax, (2) sunny places as well as shade for the summer, and (3) buildings around the park to create the sense of enclosure.

 

Border Vacuums

San Jose Main Library
H Graem © 2006

Massive single uses in a city have a common quality - they form borders. Borders in cities can make destructive neighbors. They are frequently areas of blight and stagnation.

This vacuum effect can be minimized by bringing nodes of activity up to the border area, rather than placing all of them in the use's center.

Park uses in large parks can be brought up to the border, acting as a link between the park and the bordering street. Such uses can live a charming double life. Universities could make portions of their campus border more like a seam and less like a barrier if they placed uses intended for the public at key points along their perimeter.

The combined San Jose City and San Jose State University Library at a corner of the university campus acts as key link between the campus and the greater San Jose community. Within the library lies a skylit corridor linking the street entrance visible in the image with the interior campus on the other side.

Camillo Sitte (1843-1903)

Two urban theorists discussed in this blog are among my favorites. They have been the most influential on my views of the good city.  If one wanted to examine the sources for my city visions, this is the place to start.

Camillo Sitte

Why do people come from all over the world to visit the medieval European city? This city remnant of the past is usually an unplanned urban core frequently containing castles and churches, and occasionally bounded at least in part by a surviving defensive wall. It is usually surrounded by a more modern city. What makes this ancient city so attractive? Why do people so enjoy walking itsr streets, plazas, parks and pathways? What is the secret? Camillo Sitte believed he had found the answer.

Camillo Sitte died over a 100 years ago, yet his insights into city patterns supportive of the urban environment still have value today. He is best known among urban planners and architects for his 1889 book, City Planning According to Its Artistic Principles. He strongly criticized the prevailing emphasis in European city planning of the time on broad, straight boulevards, public squares arranged primarily for the convenience of traffic, and efforts to strip major public or religious landmarks of adjoining smaller structures that were regarded as encumbering such monuments of the past.

Medieval Maastricht, Netherlands

Sitte proposed to follow the design objectives associated with the streets and buildings that shaped medieval cities. He advocated curving or irregular street alignments to provide ever-changing vistas. He pointed out the advantages of what came to be know as "turbine squares", civic spaces served by streets entering in such a way as to resemble a pinwheel in plan. His teachings became widely accepted in Austria, Germany, and Scandinavia. In less than a decade, his style of urban design came to be accepted as the norm in those countries.

The 1920s avant-garde, on the other hand, emphatically rejected Sitte’s theory. The Ville Contemporaine plan by Le Corbusier exemplified this rejection of all that Sitte believed. The centerpiece of this plan was a group of sixty-story cruciform skyscrapers that housed both offices and the flats of wealthy inhabitants.

Corbusier's Ville Contemporaine

The skyscrapers were set within large, park-like green spaces. The pedestrian circulation paths were segregated from the roadways, which glorified the use of the automobile as a means of transportation. As one moved out from the city center, smaller multi-story zigzag blocks set in green space and set far back from the street housed the workers.

Much development from the middle of the 20th Century that followed Corbusier's urban philosophy met the wrecking ball as the century's end approached. The dystopian environment associated with much of public housing from those years only ended with this cleansing destruction.

The reception to Sitte's ideas continued to be ambivalent until the 1970s, when architects and urban planners rediscovered the importance of the Viennese theoretician. This development culminated in the "new urbanism" movement which counts Sitte’s magnum opus as one of its primary historical references.

Plazas

 

Piazza della Signoria, Florence

One of Sitte's favorite cities was Firenze (Florence, Italy) and its Piazza della Signoria. Here he found design principles to apply in other cities desiring plazas with a human scale and actual usage. Some of his plaza principles were:

• Public squares should be enclosed (streets not function as the enclosure) by buildings;
• Buildings & monuments located along side of plaza, not the center;
• Plaza shape unsymetrical (irregular plaza shapes stimulate interest);
• Plaza center open (craze for isolated buildings a foolish fad);
• Streets enter at angles;
• Avoid plazas open to too much traffic;
• From any point in plaza, only one single view out of plaza possible at a time (hence only a single interruption of the enclosure as a whole);
• A plaza too small does not give due effect to monumental buildings / If too large, even the mightiest seem dwarfed in relation to it.

Piazza del Duomo, Florence
H Graem © 2017

Irregular plazas enhance naturalness, stimulate interest and augment the picturesque quality of the tableau. It is also much easier to locate monuments in them.

Plaza groupings can create special effects that result from walking about from one plaza to another in a cleverly grouped sequence. Visually the frame of reference changes constantly, creating ever new visual impressions.

Streets

 

Baker and Lyon Streets, San Francisco
H Graem © 2006

The ideal street must form an enclosed unit. One feels at ease in a space where the gaze cannot be lost in infinity. Such a principle opposes long straight streets.

Most city streets today violate this principal. An interesting exception would be in the case of hilly cities (such as San Francisco) where the rise or drop of the street on the hill in effect creates the enclosure. As shown in the photo to the right, sometimes the hills are so steep that the street becomes stairs and the enclosed sense at pedestrian scale becomes complete.

Parks

 

Parks should be hidden gardens, connected with others, guarded from the wind by the enclosing facades of high buildings (from whose windows many eyes act as protective watchers).

Public parks today are usually surrounded by well traveled streets that take away the sense of enclosure, except where the streets disappear from the view of the park user due to large park size, tree cover, and indulating topography.

Golden Gate Park in San Francisco, Balboa Park in San Diego and Central Park in New York being examples of the latter situation.

 

Cities

Tales of Future Past
David Szondy's former website,

What will cities look like some 200 years in the future? In the past, visions of the future city have been full of magnificent skyscrapers, moving sidewalks and flying cars. The reality is that the future city will be built one structure at a time and many current buildings and neighborhoods will remain.

The image to the left shows a future city visualized early in the last century.

What city exists in your dreams? What changes should occur in the way we design and develop cities? What development approaches should we continue? Which should we dump? Most important, which approaches will support the existence of creative and thriving human societies.

Urban Theorist or Urbanist

Three professions have a significant role in the creation and evolution of cities; planners, engineers and architects. These are the people that politicians and developers consult when considering changes in a city. However, there is another profession which has an overarching and profound role; the urban theorist or urbanist.

A successful permanent outdoor market in Hong Kong, China
H Graem © 2007

The internet does not clearly differentiate between the two common terms for persons who research cities and urban life: urban theorists and urbanists. Urbanist seems to be more commonly applied to contemporary theorists. I lean toward "urbanist" as a shorter title for a person dedicated to studying and planning urban life.

At least as far back as Plato, thinkers regarding success and failure among existing cities have pondered what direction cities should take in the future.  Only a few have had a broad and lasting impact upon the urban fabric.

These effective urban theorists set in motion definite changes in the established way of viewing and developing cities. In the next posts two persons are discussed who have had a lasting impact on thinking about historic, current and future cities.

Prime Actors

Reality says that the actual decision-makers in the creation of the future city are not the architects or planners or urban theorists. In the real world, the politicians, developers and financiers determine what actually gets built.

Present and future shown in Shanghai Planning Museum
H Graem © 2007

The politicians approve expenditures for the infrastructure which enables a city to function: the schools, sewers, transit, highways, seaports, parks, garbage collection and airports. They approve the plans and/or zoning which determine where and what private individuals may build. Such approval may be based on objective criteria and professional advice or who contributed to their last political campaign. Whatever the basis for the decision, it determines the appearance and environment of the city of the future.

A city will not be built without developers. Development cannot occur without funding. Development capital may be provided by private or public sources, or both. The specifics of where and what development occurs depends on the applicable general plans and zoning, the state of the local economy, the cost of land in different locations and the availability of sufficient money to fund the development project.

Too often cheap land on the city outskirts becomes major development locations. This is not because city plans encourage it, but because there lies the greatest private profit. Too often, political influence trumps the plans. Future livability and long-term cost to the city and its residents is the loser. 

The Good, the Bad and the Ugly

Image from 'The Good, the Bad and the Ugly'

This subheading is the title of one of my favorite western movies. Rather than the mythical American West, the discussion here is about urban communities  (1) to be emulated or (2) to be seen as experiments that went awry. The question is, what urban designs and approaches should be models for the future?

 

If we respect our history, culture and what works, the best of what exists will remain and be imitated elsewhere. New technology, building techniques and urban forms will be evaluated for their potential to make for success or failure in the long term.