From Green Corridor To Thick Edge: The Linear Park

This excerpt comes from Diana Balmori’s A Landscape Manifesto. Balmori Associates, her landscape and urban design firm, recently completed a nine-mile linear park on the abandoned New Haven railroad in Connecticut.

Converting a railroad corridor to a linear park results in an essential transformation of a past artifact. Though linear parks and other new landscape forms take their structure from the past, they have risen to the level of new typologies. They mark the beginning of a new landscape agenda. The example of an abandoned railway line made into a linear park or greenway will serve as the poster child of such ecological transformations.

This kind of transformation is not what it may first appear. Some members of the public consider the linear park a “greening” and the return to nature of an industrial mechanized corridor, where coal- or oil-driven engines polluted a strip of land for hundreds of miles. But the reality is more complicated. It is true that the making of the rail line into a greenway often involves planting trees along its edges and removing railroad ballast. But in most cases, the removed ballast is unfortunately replaced by asphalt, making the corridor surface impermeable, and thus ecologically a loss. Whatever vegetation is in place or is added to this trail generally has little in common with the original vegetation; it is not a return to the plant life that was there before the railway. What will grow on this line now will be vegetation which flourishes along edges. There will be many invasive plants which prosper in these situations, and the animal life will also be edge species. The greenway will also contain vegetation changed by having survived decades of application of herbicides (to keep railroad lines clear of vegetation) and by having endured diesel oil and coal emissions. As a corridor for mass transit, it could also be considered to have been a greener artifact than the resulting pedestrian and bike greenway, though its function as a space which permits people to walk and bike does enhance the quality of human life.

It is not a return to the plant life that was there before the railway. What will grow on this line now will be vegetation which flourishes along edges.

Metamorphosis is taking place before our eyes, and we are essaying a new vocabulary for what is emerging. We are taking an old cultural artifact, the product of a heavy steel and iron industry, and reverting to a hybrid system; we are taking rigid industrial systems that overpowered and separated themselves from the living systems surrounding them and allowing life to infiltrate them and transform them.


Linear parks are dynamic rather than static; they are not peaceful retreats but ways. A huge network of outworn and defunct transportation systems and public-utility corridors—canal lines, railroad lines, waterfronts, abandoned ports, utility rights-of-way—is being converted into open public space. That they have become a typology shows their success; they have exceeded and moved on from the artifact that generated them—the railroad corridor—and have spread to anything that can take a linear format.

The large-scale abandonment of railway lines across the United States gave rise to the creation of these linear parks, or greenways. The possibilities of this new form have not yet been fully explored. More appropriate to our times and culture than the traditional central urban parks of the Olmsted era, the linear park differs from them in many ways. Nonetheless, this new park, like those of the nineteenth century, continues to embody our civic ideals; today’s greenway has sparked the first truly widespread citizens’ movement concerning public space since the great park era of the 1830s to 1860s, eliciting the same broad-based grass-roots idealism and support as the nineteenth-century urban parks did. This movement has spawned citizens’ organizations that support various individual conversions of old infrastructures to new parks, as well as national nongovernmental organizations (NGOs) such as Rails-To-Trails; it has also become a strong base for another NGO, the Trust for Public Land, which has been brought in to negotiate land acquisitions from the most challenging of clients, the railroad companies.

The main characteristic of this new public space, the linear park, is above all the creation of a dynamic set of connections rather than a destination. It responds to a new stage in our thinking about transportation and to the peripatetic spirit that has long characterized American life. The linear park opens pathways to diverse neighborhoods and new recreational spaces and experiences of nature; it invites exploration of alternate modes of transport and of cultural resources. It weaves connections between city and suburb, suburb and country, and nature and culture, and among people of different origins, ages, or sexes. It is an answer to the increasing cultural isolation and physical separation in which we find ourselves.

Linear parks are the twenty-first-century park par excellence. Their implications are dramatic: for a relatively small amount of money, these narrow green corridors can reconnect parts of a city, weaving themselves through it, spreading themselves democratically to reach all areas. They can be attached to streams, rivers, or shores to provide soft edges and restore floodplains. And they function as pathways for people to travel on foot or bicycle, not as ancillaries to an avenue of cars. Though the idea of the linear park is less than twenty-five years old, it has the potential to remobilize our life in cities, encouraging pedestrian movement.

There are many other positive effects of greenways. They can foster a community of businesses along their edges, so that neighbors can once again walk, bike, or skate to the store for a loaf of bread or a bottle of aspirin. They can also provide critical migration corridors for animals through urban areas. They are active landscapes, which can introduce open, green space to various parts of the city; intensify topographic features, rivers, ridges; offer a soft surface capable of absorbing rainwater; and let people escape the car-dominated hardscape.

The transformative power of linear parks comes from the connections they are capable of producing. Up to now, linear parks have developed without arms, as straight 10- to 15-foot-wide strips along the path of an abandoned railway, canal, or utility corridor. But linear parks can also become links (either as permanent paths or as temporary one-day street closures) to museums, to bakeries, to marathons, to concerts, to state parks, to political rallies. This modest caterpillar with the capability of becoming a centipede is a landscape that can actively change a community: greening, invigorating, and connecting.

One of the chief values of the linear park is that it addresses the problem of socioeconomic separation to which the suburb contributes. Greenways, which accommodate movement on foot or bike, might be possible restitchers of the urban fabric, joining urban centers and suburbs to one another recreationally and culturally, providing the continuity of a common space. The linear park enhances the character of all the neighborhoods it connects. It might provide an outdoor activity for people in a medical or child-care facility, or offer space for educational and aesthetic activities for children, teenagers, or the elderly. In other words, an interplay can be achieved between continuity and locality, in response to the specific needs and characteristics of each neighborhood it transverses. In this way, the linear park can offer many different experiences.

For a relatively small amount of money, these narrow green corridors can reconnect parts of a city, weaving themselves through it, spreading themselves democratically to reach all areas.

In a time when open land is being voraciously consumed by suburbs and unending construction, the linear park extends a continuous living and healing linear public tissue. It is a habitat corridor which fosters life rather than expanding and isolating suburbanization, a continuous path through city, suburb, and farmland. Along greenways, the direct human experience of the landscape, which had often been lost in the industrial age, is recaptured. It is not simply a modest tweaking of our concept of the park, but a major reconstitution of the way we use space and time and of how we view transportation. We cannot yet imagine the consequences of this transformation. By converting these corridors into havens for pedestrians and cyclists, we are no longer relegated to the sidewalks along highways, but become the shaping force of the corridor, free from all machines other than those powered by our own energy.

This new park system, with human motion at its heart, promises to be economically productive. The linear park energizes areas around it, just as the railroad and highway before it did. Though it invites dense development along its edges, we have the opportunity to think about how we wish to implement and direct that growth. The linear park can increase land values and attract premium residential areas around its perimeters, just as nineteenth-century parks did. At the same time, however, the continuity and length of these corridors also lend themselves to a variety of commercial and institutional uses. Moreover, there is a political potential in these parks, as new avenues to community empowerment.

The originality of the linear park is to be expressed, not buried in ideals and agendas of the past. I think it is not too idealistic to propose that clean energy sources be used to build greenways; that linear parks should be drained, planted, built, and maintained to restore a healthy environment; that they thus become reliable refuges in which plants, animals, and people can thrive. We can, in these modest strips of land, create a blueprint for the life we wish for ourselves.

One valuable aspect of linear parks is that they stem from local initiatives. It requires a group of motivated citizens who band together, pay for a regular newsletter, and pressure their local government to acquire abandoned corridors of railroads and canals. This is often a slow process. In the case of the Farmington Canal in New Haven, Connecticut, it took more than 15 years, and progressed bit by bit. These projects shepherded by citizens’ groups, moving gradually but persistently, are a lesson about American society’s potential for action.

This new landscape at city scale has already entered the urban fray, putting citizens’ associations, politicians, railroad companies, NGOs, and state DOTs in one jousting arena. The conflicts and their resolution are not to be taken for granted. Though the citizens’ movement has been successful in many instances in obtaining the land from the railroads, there have been many compromises: the land in most cases is simply being banked for new public transportation systems. Also, the majority of these projects receive external funding (one million dollars a mile), which has meant that only their use has been transformed; no aesthetic language has been developed for them as a new modern typology. The work of transformation usually consists in making a narrow band—typically 15 to 20 feet—of asphalt pavement with some markings or signs at road crossings, thus creating paths for bikes and pedestrians. For a landscape’s new typology to succeed, landscape artists need to enter a battlefield of competing interests and experiment with alliances to shift economic interests toward it. 2 These struggles and partnerships are not only with client groups, but also with others who have the various types of professional expertise needed to create a new typology. The economics for linear parks have kept them from developing a landscape aesthetic which reveals the new sustainable relations between humans and nature. They still speak the old language of suburban “nature” trails, echoing an old relationship with nature.

Diana Balmori is the principal of Balmori Associates and author, most recently, of Groundwork (coauthored with Joel Sanders). On December 8th, she’ll be part of a discussion, “Urban by Nature: Healing the Landscape/Architecture Divide in NYC,” at the Museum of the City of New York.

Images courtesy of Balmori Associates. Author photo by Margaret Morton.