U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: FHWA-HRT-11-004 Date: May/June 2011|
Publication Number: FHWA-HRT-11-004
Issue No: Vol. 74 No. 6
Date: May/June 2011
A one-of-a-kind curved pedestrian bridge drew attention to a downtown waterfall and capped off the rebirth of Greenville, SC, into an exemplary livable community.
|Arguably the most photographed landmark in Greenville, the pedestrian Liberty Bridge is the keystone of Falls Park and the downtown redevelopment.|
Simply put, downtown Greenville, SC, is a striking success story of how a community reinvented itself. A key component of the transformation was the replacement of a highway overpass with a dramatic pedestrian bridge. Here is the story of decay and rebirth and how the city accomplished its transformation to a sustainable community.
In the mid-20th century, Greenville's downtown along Reedy River experienced a severe decline. As was the case in many communities throughout the country, the downtown no longer was the city's major retail hub, and even though Greenville was thriving, Main Street was not participating in that growth. Walking down Main Street today, it is hard to believe that this tree-lined avenue, bustling with activity, was once mostly vacant.
The community had turned its back on the riverfront and its unusual waterfall, which cascades through a wooded valley in the heart of town. The water was polluted and the riverbanks littered with debris and trash. In 1960, a four-lane highway overpass, the Camperdown Way Bridge, was built across the waterfall, obstructing the view of the picturesque falls and creating a barrier to public access.
|In this wooded valley in the heart of town, now called Falls Park, visitors stroll through multilevel terraces to the stunning Liberty Bridge just downstream from the waterfall (center of photo).|
Clearly, action was needed. Faced with the slowly declining business district, Greenville leaders chose to partner with private developers to recreate the downtown in a model of sustainable redevelopment. In doing so, they created a livable city with a range of amenities rarely found in a community of 60,000 people. In short, Greenville set out to remake Main Street and create an atmosphere that would be conducive to entertainment and the arts, and attract offices, residential condominiums, and specialty retail businesses. Greenville's award-winning downtown affords a bricks-and-mortar testament to innovation.
"Greenville embraced the concept of redevelopment, making the city one of the early pioneers in reclaiming the prominence of its downtown," says Division Administrator Bob Lee of the Federal Highway Administration's (FHWA) South Carolina Division Office, "In the process, the city replaced a highway overpass with a landmark suspension bridge for pedestrians. Liberty Bridge curves in a sweeping arc just downstream from a waterfall, taking advantage of a unique natural feature."
While some cities work to maintain their distinct identity, Greenville had to work to uncover its uniqueness. In 1967, the Carolina Foothills Garden Club, with support from the city and Furman University, set out to bring the falls back to life. Furman University donated 6 acres (2.4 hectares) surrounding the falls, and in return the city agreed to create and maintain a park. The downtown took another turn for the better in the mid-1980s when the garden club and the city a-dopted a master plan for Falls Park, designed to restore the beauty of the area and provide a safe and welcoming public gathering spot.
Meanwhile, the Main Street streetscape project, completed in 1981, marked the first physical improvement. Through what would be considered a "road diet" today, the designers reduced Main Street from four lanes to two and widened the sidewalks for easier walking and outdoor dining.
Street trees were planted to further enhance the pedestrian experience, and parallel parking was replaced with free angled parking. The trees, which are now a signature element of Main Street, made it appealing to pedestrians and also screened some of the vacant and unattractive buildings. Further planning laid the groundwork for investments in plazas and public spaces and focused on highlighting one of the most spectacular features of Greenville's downtown—the Reedy River with its impressive series of natural waterfalls.
With its new image in place, the city recognized the need for the public sector to step forward to provide the impetus for private investment. In 1982, the Greenville Commons/Hyatt Regency project created the city's first luxury convention hotel located directly on Main Street. Funded through a public-private partnership, it became a visible manifestation of Greenville's faith in the future of the downtown.
In 1990, The Peace Center for the Performing Arts, located on the banks of the Reedy River, opened as a result of a joint partnership of the city, county, and State governments. The arts complex not only stabilized a less-than-desirable part of town, but also triggered redevelopment on the south end of Main Street and linked downtown to its hidden assets—the river, park, and waterfall.
|These pedestrians are strolling Main Street during one of Greenville's frequent arts and crafts fairs.|
Around that time, the city established an ad hoc task force to review the impact of removing the Camperdown Bridge. In the mid-1990s, the city and the Carolina Foothills Garden Club commissioned Washington, DC, landscape architect, Andrea Mains, to create a redevelopment plan for the park. Introducing the concept of transforming Falls Park into a regional attraction, her plan involved turning the passive green space into a major public garden. The plan presented the natural beauty of the falls and a world-class pedestrian bridge as critical components of the design. Support for the plan was confirmed in the 1999 Reedy River Corridor Master Plan.
At the time, the Camperdown Bridge was structurally adequate and in reasonably good condition but carried very little highway traffic (5,600 vehicles daily). Early on, the city approached FHWA and the South Carolina Department of Transportation (SCDOT) with a request to allow demolition of the federally funded structure. As the project champion, the city commissioned a transportation study evaluating the need for the bridge. After reviewing projected travel demand and the age of the structure, and taking Greenville's livability vision into consideration, FHWA agreed to support the project if the local government and metropolitan planning organization (MPO) could vote to support removal of the bridge. As with many metropolitan areas, the MPO provides a roundtable for transportation discussions and decisionmaking in the Greenville area. Having been involved in a support role during the project development, the MPO passed a resolution supporting demolition.
|Camperdown Bridge, shown here before its demolition, shaded the waterfall through most of the day so that many Greenville residents were unaware of their city's hidden asset.|
Subsequently, in 2001, the Greenville City Council, working with SCDOT and FHWA's South Carolina Division Office, agreed to close a portion of the adjacent street to make way for removal of Camperdown Bridge as a prerequisite to the park redevelopment.
In 2003, Mayor Knox White announced a funding campaign for Falls Park. The fund was to provide a source of revenue for ongoing enhancements and programs, and the interest earnings were to be used for park expenditures above and beyond the city's normal park operating budget. At that time, individuals and corporations had already pledged $2 million to the endowment, with the most significant naming rights going to a new curved suspension bridge. The city announced that the bridge would be called the Liberty Bridge, in honor of The Liberty Corporation founder W. Frank Hipp and his children for their commitment and contributions to the Greenville community.
The city's hospitality tax, levied on prepared meals and beverages sold in Greenville, funded the $4.5 million structure. By South Carolina law, the hospitality tax must be used for tourism-related activities and improvements.
|To reach the suspension bridge and view the scenic waterfall, these pedestrians walked down from Main Street through 20 acres (8 hectares) of terraced gardens and flowerbeds.|
Bridge architect Miguel Rosales, AIA, president of Rosales + Partners of Boston, MA, designed the bridge; Schlaich Bergermann and Partner did the engineering; and Taylor & Murphy Construction Company, Inc., built the bridge. The park's different levels step down through gardens to provide various access points to the bridge. The architect designed the structure to create a dramatic aerial platform for viewing the falls and gardens. Local soil conditions and topography played an important role because the architect wanted the design to fit seamlessly into the landscape.
From conception to detailed construction documents took about 3 years, including an extensive review process by city officials and residents. Construction took about 14 months and was completed in 2004.
Liberty Bridge is 345 feet (105 meters) long and 12 feet (3.7 meters) wide with an 8-inch (20-centimeter)-thick, concrete-reinforced deck supported by a single suspension cable. The deck's distinctive long sweeping curve has a radius of 214 feet (65 meters) and is cantilevered toward the waterfall from the supporting cables on the outside of the curve to allow unobstructed views of the falls. The deck is a ramp that rises 12 feet (3.7 meters) or 3 percent from east to west as it crosses the river.
Three primary cable systems work with and against each other to support the bridge and hold its position in space. Underneath the deck are three 3-inch (80-millimeter)-diameter ring cables that support the deck and also place it into compression in the horizontal plane. Working against the ring cables in the horizontal direction, but with them in the vertical, are 1.18-inch (30-millimeter) hanger cables. The hanger cables are set from 35 degrees to 60 degrees from vertical and are supported by the catenary or main cable. The main cable is actually three separate 3.15-inch (80-millimeter) cables—two spanning from the abutment blocks to the steel mast and one spanning from mast to mast in the center of the span.
Two 90-foot (27-meter)-tall masts weigh more than 28 tons (25 metric tons) each and incline away from the bridge at a 15-degree angle. Two 3-inch (80-millimeter) backstay cables hold the masts in position. Steel piles and rock anchors, some 70 feet (21 meters) deep into bedrock, transfer the bridge loads to the ground at the abutments, mast, and backstay foundations. The architect concedes that the diameter or cross section of the steel towers could be a bit smaller, but in general he is satisfied with the end result.
|A clear span of 345 feet (105 meters) between the abutments makes the bridge appear to float above the landscape, a dramatic effect accentuated at night by specially designed lighting.|
The bridge is mostly steel, with smaller and more slender members than most bridges. The engineering firm conducted a detailed study of the characteristics and performance of the cables to find the best configuration and to balance aesthetics and functional considerations.
The elegant curve required extensive calculations and analysis to ensure balance of the forces between the cable above the deck and the three ring cables under the deck that connect to the steel truss. The stiff steel truss helps stabilize the structure during use. The bridge does vibrate and sway slightly, but not uncomfortably; in fact, it moves more when fewer people are using it. About 1,300 can stand on the bridge at a time safely, according to the architect. "We used high levels of safety standards well beyond the actual physical live load capacity that the bridge can accommodate," Rosales says. "All possible live and dead loads needed to be considered, because small vehicles such as bicycles also can use the bridge."
The bridge's soft blue lighting is integral to the experience of crossing the bridge at night. "The light transforms the appearance of the concrete walking surface, making it appear much softer and more delicate," says Rosales.
"Although bridges with similar structural concepts have been built in Germany and Spain, the Liberty Bridge is distinct in its geometry," says Rosales. "There is nothing like it elsewhere in the United States."
The bridge serves as the park's focal point, overlooking Reedy River Falls where Richard Pearis, Greenville's first European settler, established his trading post around 1770. The beauty of the waterfalls and gardens is enhanced by the bridge's graceful lines and the appealing stonework used throughout the park.
Enthusiastic crowds gathered in downtown Greenville on September 10, 2004, to celebrate completion of the $13.4 million renovation of the park and landmark pedestrian bridge. "Falls Park and the beautiful Reedy River Falls have regained their rightful place of prominence in our city," said Mayor White at the dedication ceremony. "I invite everyone to visit the park, take a walk on the bridge, and enjoy this spot that is the birthplace of Greenville."
|Reedy River Falls is now accessible to visitors and residents alike, making for a water experience that is unusual in the heart of a city.|
Falls Park and the Liberty Bridge did for South Main Street what the convention center and streetscaping did for North Main Street, accelerating development along the river. The park and bridge sparked a $65 million development, RiverPlace, completed in 2005 and marking the city's largest public-private partnership to date. Located on the banks of Reedy River, the development consists of condominiums, offices, retail shops, artist studios, restaurants, and a hotel. A garage is located beneath the building, and public walkways and plazas link RiverPlace to Falls Park. "RiverPlace is environmentally sensitive to the site and established a design standard for the community," says Nancy Whitworth, director of the city's Economic & Community Development Department.
Falls Park and Liberty Bridge serve as a major tourist destination and Greenville's signature postcard setting. The city estimates a minimum of 1 million visitors have enjoyed Falls Park since it opened, and potential private investment in the immediate area could reach 10 to 20 times the public investment.
"The success of Main Street and downtown Greenville is a result of 30 years of hard work and strong partnerships between the public and private sectors," says Whitworth. "Greenville has focused on creating a vibrant downtown that is authentic, sustainable, and most important, designed for people. Together, the city and community have been able to realize Greenville's potential and capitalize on its uniqueness."
Liberty Bridge Awards
Jessica Hekter is the manager of the planning, air quality, and right-of-way programs at FHWA's South Carolina Division. She holds a B.S. in community and regional planning from Iowa State University.
Leslie Fletcher is the communications manager for the city of Greenville. She holds a B.A. in English from Clemson University.