In recent years, urban renewal projects have been proposed with more than one goal in mind. Replacement and fortification of decaying infrastructure is one motivation, but an increasing number of projects have a greener purpose. United States highway removal projects now tend to combine removal of redundant or decaying concrete roadways with the creation of parks, boulevards or other environmentally friendly alternatives. Making a case for such reconstruction is the city of Seoul, Korea, where the Cheonggyecheon expressway was converted into a beautiful park. Studies of the results of the conversion have revealed a startlingly positive environmental impact.
The Congress for the New Urbanism (CNU) has compiled a list of the 12 “most wanted” highways in the United States; these roadways harbor the most potential for green renewal. A second compilation of highways has also been created; the following “top 10” list of highway projects is ranked according to degree of completion:
- Route 195, Providence, Rhode Island
- US 40 “Highway to Nowhere,” Baltimore, Maryland
- I-40 Crosstown Expressway, Oklahoma City, Oklahoma
- West Shoreway, Cleveland, Ohio
- Route 99/Alaskan Way Viaduct, Seattle, Washington
- Route 29, Trenton, New Jersey
- Downtown Crossing/Route 34, New Haven, Connecticut
- I-84 Aetna Viaduct, Hartford, Connecticut
- Claiborne Corridor, New Orleans, Louisiana
- I-895/Sheridan Expressway, New York City
A major portion of the construction for the first three listed projects has been completed, and plans for the reclamation of the resulting cleared areas are now in development. The remaining seven projects have been approved and are currently in the design and analysis phase.
These highway removal projects—and many others like them—center on the idea that the most cost-effective strategy for dealing with the continually decaying and obsolete urban highways is to replace them. The proposed alternatives take advantage of mass transit, provide multiple transport modalities, actively reduce pollution and decrease traffic congestion. Examples of such alternatives include:
- Urban Communities
Renovation and replacement projects such as these will provide significant benefits to their parent communities. Such benefits include:
1. Decreased Heat Trapping
Removing the large mass of concrete that made up the original highway surface can result in a significant decrease in the ambient temperature of the community.
2. Decreased Large Particulate Pollution
Eliminating the particulates generated by the multitude of cars traveling over the highway decreases ambient pollution by a considerable degree.
3. Improvement in Mass Transit Systems
When highways are removed, the opportunity presents itself to expand and improve mass transit systems. This shift from automobile to other forms of transportation has been associated with decreased pollution and significant energy savings.
4. Decreased Traffic Accidents and Delays
The removal of a high-speed, congested highway has the immediate effect of decreasing the number of costly traffic accidents and injuries associated with such a thoroughfare.
Highway removal and reconstruction is a cost-effective method of dealing with aging urban infrastructure. The transition from highway to boulevard, park or community has economic, environmental and cultural advantages that make such changes appealing to both urban planners and environmental consultants. The CNU “Freeways Without a Future” database contains hundreds of examples of highways that are prime candidates for such removal and renovation.