The Green Line: Transforming Broadway into a Linear Park

                                                              

The Green Line: Transforming Broadway into a Linear Park

x
Solution proposed by: 
Jonathan Cohn, AIA, LEED AP, Principal; Jung Hyun Woo, M.Des ‘16, Harvard Graduate School of Design
In a Nutshell: 
The Green Line proposes transforming NYC’s Broadway, a “bonus” street cutting diagonally through the city’s grid, into a new linear park. This new place can be an inclusive, walkable, sustainable, public asset providing for a wide range of activities: bike paths, gathering places, lush planting amid permeable pavers and bio‐swales.
Where and When: 
The Green Line is a vision for transforming an existing street—Broadway in NYC between Union Square and Times Square—into a new type of urban park. It could start as a pilot project on a few blocks, and be phased in over time.
Challenges: 
In the history of cities, the advent of the private automobile is relatively recent. Many cities are struggling to find the right balance between mobility, transit, public safety, and public space while making cities more equitable, livable, and sustainable. The Green Line is proposed because Broadway is not needed for surface automobile traffic, and could provide a series of great new outdoor spaces to be used in a range of ways by nearby workers, residents, and visitors at all times throughout the day.
Innovation: 
This project proposes a new type of urban park: a Street/Park. Not a High Line separated from surface activity, but a Green Line fully integrated with the life of the city. It is informed by precedents of great streets, such as Las Ramblas in Barcelona. And it builds on earlier experiments in NYC and elsewhere to transform city streets into public space accessible to pedestrians, but by aggregating a series of small initiatives it provides an overarching identity for a new public place.
Concept: 
Starting as a ridge‐line trail through the original landscape, Broadway was the city’s first land route, allowing for the development of the Island northward. The importance of Broadway as the major commercial and transportation spine of the city persisted into the 20th Century. Only recently has this paradigm shifted, suggesting a new way of conceiving of the public realm along this historic public way. The city grid works fine for traffic without Broadway. This space can now be better used as a new type of linear at‐grade public park. So why a park? New York City’s park system, including large assets like Central and Prospect Parks, is just too small for the burgeoning demand. In addition to squares and parks, it is the streets that provide the public space for city life. Allowing for emergency access and crosstown traffic, the project draws on historic precedents of streets as great public places, integrating landscape into city streets in a way that improves the environment and prioritizes the pedestrian experience. We envision lush planting, but also playgrounds, dog runs, a running and bike path, performance areas, and sitting areas; a great new asset for businesses and new residential areas fronting it.
Description: 
Broadway may be the street people around the world connect with New York, but it wasn't included in the original grid plan that has shaped Manhattan for the past 200 years. The Commissioners’ Plan of 1811 superimposed an orthogonal geometry on the unbuilt Island of Manhattan, not recognizing either the natural topographic features of the land or existing property lines. The grid was intended as the means to develop land: the grain of the grid and the subdivision of property within each block was at a manageable scale for many developers to harness the capital required for new construction. Today, of course, developers, capital markets, and advanced construction techniques can easily manage much larger sites. But despite its tall buildings, the scale of New York’s streets and blocks remains decidedly 19th Century. The current grid, sans Broadway, works perfectly well for development and surface transportation. Broadway is an extra street, a public space cutting diagonally through a standardized urban form. This lower stretch of Broadway, spanning roughly from Times Square to Union Square, also represents an excellent swath to introduce groundwater recharge. Rather than allowing stormwater to enter the underground sewer system, where during heavy rain and snow storms it combines with untreated wastewater and discharges directly into the city’s waterways, much of the runoff could be allowed to percolate directly into the earth. Recognizing a need for publicly accessible open space throughout the modern city, The Green Line proffers the next phase of life for this “bonus” street in a post‐industrial city. As a linear street/park, the project would provide much needed shared outdoor space that would provide for a wide range of new social activity, transforming an unrealized asset into a new social activator, to be used in a new way every day by residents and visitors alike.
Impacts: 
As a research project, the vision for the Green Line has already contributed to an ongoing discussion about potential transformations of public space in cities. The hegemony of the private automobile in public space is being challenged, a new balance between all modes of transit and public use is being suggested. Although this is a site specific proposal, the potential applications of the approach are global.