To better describe what a greenway is, it is best to explore their history. This history can be viewed as passing through three generations. The first extends from some of the earliest urban developments to the first half of the 20th Century. This generation is defined by the historical use of the axis and boulevard as an organizing urban design element that created “formal, ceremonial routes that tried to reintroduce nature into the city” while linking important architectural and cultural features (Searns, 1995).
Examples are found in ancient
, in Rome , and the Versailles all leading to the notion that the corridor itself can become a special event (Searns, 1995). Some of the earlier inspiration can also be found in the burgeoning urban settlements of the Renaissance period where “walkways and spaces were created near rivers for sunlight, air, and view” (Searns, 1995). These open air and at times naturalized places, as well as the European boulevards, and even the canals of Champs Elysees , Amersterdam, and St. Petersburgh all connect important geographical features and acted as muse for designers such as Frederick Law Olmsted. Venice
Having traveled extensively in Europe Olmsted’s ideas for tree lined links in and around places like
and Berkely promoted the parkway and a parkway system as not only a corridor but its own experience. Perhaps the most well known of these plans is the Emerald Necklace of 1876 in Boston (Fabos, 2004). , Boston MA
In the mid to late 1800s, around the same time Olmsted was exploring his ideas about the parkway, there were efforts being made by New York State to adopt the “blueline concept” (also referred to as the greenline concept) to create the Adirondack Park. The “blueline concept” was essentially a blueline drawn on a map designating and limiting the extent of urban growth north though
(Zube, 1995). The Library of Congress cites the New York State model as the “genesis of the greenline concept and therefore a benchmark of the genesis of the greenway concept.” The Adirondack Park consists of pockets of highly regulated development surrounded by vast amounts of undeveloped lands and linked by limited roads and an extensive off-road trail system (Zube, 1995). Adirondack Park
In 1898, Ebenezer Howard adapted the
model when developing his Garden City. The greenbelt he envisioned encircling his new urban form was meant to function more like a blueline and less like a green link within and around the city (Zube, 1995). It is important to note that this greenbelt was intended to function much like a greenway in that there was a determined introduction of nature into urban life. In the early 20th century the popularity of the automobile, and separatist notions of the Garden City and blueline led to the advent of the next generation of greenways that looked to create separate corridors for pedestrians and automobiles (Searns, 1995). Adirondack
|Kelley Drive Gree|
The physical design of greenways also changed during this time. Beginning in the 1970’s, walk/bike trails (multi-use trails) were constructed with a smooth surface, usually asphalt, about 8’ in width. The smooth surface was intended to accommodate the popular, narrow tired bicycles of the time. The trails began to widen and the materials began to vary as bicycle tire widths increased and more and varied types of users began to use the trails.
|American Tobacco Trail. |
Image courtesy of Greenways Inc.
In addition to the riverside or park urban greenway, this generation saw the rise of the road system give way to abandoned rail tracks and the subsequent reuse of these tracks as non-motorized corridors. The Rails to Trails movement developed during this time and was spearheaded by National Rails to Trails Conservancy (Searns, 1995). These contiguous preexisting corridors proved to be key in the promotion and adaptation of the greenway as a dynamic urban form.
As design and implementation of the greenway model evolved along with urban development, the third generation of greenways developed as a synthesis of the previously assumed benefits of connected open space. Scientific research began to prove many of the claims greenway proponents had been exposing. Current greenway theory suggests that greenways are multi-objective linear open spaces that promote not only an aesthetic, but contain restorative aspects of nature, recreation, and ecological stewardship (Searns, 1995). This generation spun off of the writings of the McHargh and Forman as well as the current data on habitat protection, flood hazard reduction, water quality, historic preservation, education, biodiversity maintenance, human health, and economic benefit (Searns, 1995).
The strength of the evolving “greenway concept is lies in its diversity of form and function” and the multiplicity of uses and users (Flink, 1993). The most cutting edge greenway development is occurring in conjunction with the reengineering of degraded watercourses. When used in conjunction with watershed protection and stream restoration, this concept can spread into surrounding neighborhoods in the form of natural, or “green”, stormwater infrastructure retrofits. As part of this multi-objective endeavor, the urban stream restoration is itself promoting an adaptation from an urban form that in many cases functions in opposition to the ecological viability of everything downstream from its location.