28th/31st Avenue Connector

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SHOWCASE

Bridging the Gap

28th/31st Avenue Connector GRESHAM, SMITH AND PARTNERS

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For several decades, Interstate 40 and a CSX railroad line separated the North Nashville and West End communities, limiting social and economic interaction between the two. Nashville leaders and community members had long called for an overpass that would reconnect the two areas and bring new vitality to these economically depressed neighborhoods. In 2009, when Mayor Karl Dean renewed Nashville’s commitment to sustainable transportation and decided to build the connector, Metro Nashville Public Works selected GS&P as the primary designer and engineer for the highly anticipated project.

CLIENT

Metro Nashville Public Works

LOCATION

Nashville, Tennessee

MARKET

Transportation

SERVICES

Bridge Design Civil Engineering Lighting Design Roadway Design Schematic Design Surveying Sustainability Traffic Modeling Transportation Planning

TEAM PIC Michael A. Flatt, P.E. PM Diane Regensburg, P.E. PP Jonathan Haycraft, P.E., CPESC PP Ted A. Kniazewycz, P.E.

Nitaya Chayangkura, P.E. Thomas J. Carr David L. Fergus Cynthia Frear Thang V. Pham Dowell Hoskins Squier, P.E. Wes Stanton C.J. Tong, EI Mark H. Washing, P.E. Gary Young

AWARDS

2013 Honor Award - Transportation ACEC of Tennessee

GS&P had been involved in planning scenarios for connecting 28th and 31st Avenues for over a decade,” says Michael Flatt, GS&P transportation division vice president and principalin-charge on the project. “When the project finally got the green light and Metro Nashville brought us on board, we immediately began to determine key goals and objectives.”

Initial discussions with the client and Nashville leaders addressed the need for a connector that not only incorporated sustainable design principles, but also accommodated multiple user groups with dedicated pedestrian, cyclist and vehicle lanes. To determine the needs of each group, a detailed study was conducted within the site limits of the planned connector. The project’s functional design requirements were ultimately established based on traffic analyses conducted during the study.

Impacts to the existing intersections at 28th Avenue/Charlotte Avenue and 31st Avenue/Park Plaza were also analyzed, and lane configurations and future access requirements were recommended.

“Because of the economic and sociological significance of the connector, we wanted to design something more than the traditional roadrailroad overpass,” says Flatt. “We could have easily connected 28th and 31st Avenues via a standard black asphalt road with a concrete bridge deck. We could have developed a typical closed-drainage system to carry away the runoff. Instead, the team elected to create a signature street for Nashville that was like no other.”

The connector incorporates Complete Streets principles not only by accommodating multiple user groups with dedicated pedestrian, cyclist and vehicle lanes, but also through sustainable features like bioswales and rain gardens.

Accommodating the new connector within the existing development would prove to be one of the most challenging design aspects of the multifaceted project. The site required that the connector be threaded horizontally between the Hospital Corporation of America (HCA) campus, and vertically between a CSX railroad line and overhead transmission lines. The project would also require extensive coordination with property owners along the corridor such as HCA, and multiple public agencies, including Metro Public Works, Metro Water Services, Metro Arts Commission, the Metropolitan Transit Authority and Metro Parks and Recreation.

“The connection itself was not the only challenge,” explains Flatt.

“One challenging aspect of the project was working with such a large number of stakeholders. Our client, Metro Public Works, charged our team to engage with every stakeholder, listen to their concerns and provide solutions that would enhance the function of the design. And each group justifiably had a different priority.

For Metro Transit it was about serving their patrons. For Metro Parks it was about people being able to walk or ride their bikes across the bridge and connect to Centennial Park. For the existing businesses it was about keeping their business fully functioning during construction.”

To address HCA’s needs, the GS&P team designed an extra entrance for the campus and reconfigured the parking lot design to

accommodate high parking turnover. Designers also worked with HCA’s requirement that a pedestrian pathway be maintained throughout construction between its parking garage and Charlotte Avenue.

“The variety of perspectives ultimately enhanced the design,” says Flatt. “But we had to carefully balance those perspectives, blend them together, and then do what was best for the community.”

Throughout the project, the GS&P team worked closely with all stakeholders to ensure that project goals were met. Stakeholder meetings were held once a month in addition to several meetings each month among the client, design team and consultants.

Bright green graphics and rose-colored concrete were used to help cyclists and motorists differentiate between paths, keeping cyclists safe.

PROPOSED STORMWATER DETENTION

11’ WIDE TRAFFIC CALMING LANES

8’ FENCE AND CONNECTOR-THEMED ART INSTALLATION

HCA DATA CENTER

BIOSWALE

MTA BUS STOP

BIKE LANE

RAIN GARDEN WITH NATIVE, DROUGHTRESISTANT PLANTS

NEW SIGNAL CONNECTORTHEMED MTA BUS STOPS

NEW SIGNAL

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HCA PARKING GARAGE ACCESS UNDER BRIDGE

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HCA CAMPUS

CENTENNIAL PARK

“The bridge connecting 28th Avenue and North Nashville to 31st Avenue and West Nashville is more than just an infrastructure —it’s a symbol of bringing our community together.”

—MAYOR KARL DEAN

COMPLETE STREET – SUSTAINABLE DESIGN

MAGNOLIA-THEMED MTA BUS STOPS

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EXISTING SIGNAL

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N AVE Construction and design solutions were implemented to accommodate surrounding businesses and public agencies. Metro Transit is able to serve patrons through six new bus stops. Metro Parks’ patrons can walk or ride bikes across the bridge into Centennial Park. HCA received a new entrance and extra parking.

SHOWCASE SIX

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The 28th–31st Avenue Connector represents one of the first applications of Complete Streets planning and design in the Nashville metropolitan area, bringing one of transportation’s fastest-growing trends to the city.

“It’s a part of our global expertise to be multimodal in our approach,” says Flatt. “We had previously written Complete Streets manuals both for Louisville and Knoxville, and determined that its concept of accommodating all user groups—pedestrians, cyclists, motorists and transit users—was a natural fit for Nashville’s new connector.”

In an innovative application of Complete Streets theory, the GS&P design team used bright green graphics and rose-colored concrete to differentiate designated bike paths, helping drivers and cyclists stay safely within their respective lanes. In an inventive use of technology, designers embedded LED delineator lights between the bicycle and pedestrian pathways to provide safe lighting while minimizing environmental impacts. Each of these unique applications contributed to the larger project goal of building the connector as a model for the future of Nashville street design.

“Not only is the connector one of Nashville’s first Complete Streets, it’s also one of the greenest streets in the city,” says Flatt. “And that’s largely because of the focus on limiting stormwater runoff and pollution.”

In keeping with Complete Streets and sustainable design principles, the design team slightly narrowed the connector’s lane widths from 12 to 11 feet to help calm traffic and reduce impervious asphalt surfaces.

CSX’s requirement for an eight-foot safety fence created the opportunity for a more imaginative solution. Artist David Dahlquist designed artwork for the fences and three bus shelters themed around weaving and quilting as a metaphor for reconnecting a community. Magnolia-themed bus stops were designed by artist Kevin Berry.

Curb cuts were designed to direct stormwater to rain gardens and bioswales, which filter runoff through plantings and engineered soil layers, minimizing the amount of street pollution entering tributary systems.

Concrete dams were spaced every 30 feet to slow stormwater flow and allow pooled water to soak into the filtration systems.

Less costly in the long run than non-native varieties, naturally drought-resistant plant species were used throughout the rain gardens and other landscaping on the corridor. Striving for low-impact construction, the design reused an existing building foundation as part of the new roadbed, averting the emissions and waste that would have been generated by demolishing and disposing of the foundation.

A UNIQUE CANVAS Centering on themes of connectivity, artwork for the connector bridge was designed by Iowa-based artist David Dahlquist. Themed around weaving and quilting, the distinctive design serves as a meaningful metaphor for reconnecting these communities.

“The railroad required that a safety fence at least eight feet in height be attached to the bridge over the railroad tracks,” says Flatt. “The specs called for a traditional chain-link type fence. We took that spec and said, ‘Hey, here’s a place where we can do something creative to dress up the area.’ So we intentionally designed the fence to look nothing like your typical chain-link barrier, and made it sturdy enough to include artwork.

“The connector is an excellent example of how good design can truly transform a community. It’s also a lesson in how you don’t always have to do everything just like you did it before.”

—MICHAEL FLATT

DESIGNED FOR GROWTH the city is trying to accomplish in that area. For instance, the new Lentz Public Health Center is in that redeveloped location between Charlotte and the railroad. The new connector gives people a safe and convenient way to get from there to the West End area by car, bus, bicycle or foot.”

SHOWCASE SIX

A pivotal centerpoint between North and Southwest Nashville, the 0.3mile connector signals a new era of community interaction. Completed for $6.3 million—well below the $7.4 million estimate—and ahead of schedule, the long-awaited project far exceeded the client’s initial goals and design expectations, and gave the public the socioeconomic connector it so desperately needed.

“The bridge connecting 28th Avenue and North Nashville to 31st Avenue and West Nashville is more than just an infrastructure—it’s a symbol of bringing our community together,” declared Nashville Mayor Karl Dean at the ribbon-cutting ceremony. “The bridge reconnects two vital parts of Nashville, which will accelerate economic activity around that area. With this project, we have set a new standard for how to design and construct a signature street in our city. It has turned out to be one of the most attractive thoroughfares in all of Nashville.”▪

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“The Metro Arts Commission was then able to solicit proposals from artists nationwide, offering the fence as a blank canvas for their work. The artists were asked to think about the history of the area and the role that ‘connection’ played in bringing the neighborhoods together. When you’re driving down that roadway, the fencing doesn’t even resemble a standard enclosure that’s designed to keep people from throwing things onto the tracks. It looks like a thoughtprovoking piece of artwork.”

Transit shelters located near the 31st Avenue bridge approach also feature Dahlquist’s connectivity theme using giant needles to form a gateway to the connector. Magnoliathemed shelters located at the 28th Avenue and Charlotte intersection were designed by Phoenix-based artist Kevin Berry.

Along with its environmental focus, the innovative connector aims to promote positive social and economic change within surrounding communities. The overpass greatly improves traffic flow between the North Nashville and West End communities, and provides universal connectivity to area resources, including the interstate system, six universities, several hospitals, two major parks and numerous local businesses.

The design team also equipped the corridor both for current and future development demand. An intersection at the north end of the corridor offers room for future growth and is designed to accommodate significant traffic with left-turn lanes on both sides of the intersection. A large, regional healthcare and education hub, fittingly named “oneC1TY,” is set for development at this location.

“The connector is an excellent example of how good design can truly transform a community,” says Flatt. “It’s also a lesson in how you don’t always have to do everything just like you did it before. We didn’t just construct a large, grey bridge in the middle of a landscape that would have taken away from the beauty of Centennial Park. We designed a visually appealing, eco-friendly connector that links two previously detached communities, and enhances what

ABOUT US

Gresham, Smith and Partners provides design and consulting solutions for the built environment that contribute to the success of national and international clients. For more than  years, GS&P has focused on enhancing quality of life and sustainability within our communities. GS&P consists of industry-leading professionals practicing architecture and engineering design as well as scientists and highly specialized strategic and management consultants in Aviation, Corporate and Urban Design, Environmental Services, Federal, Healthcare, Industrial, Land Planning, Transportation and Water Resources. GS&P consistently ranks among the top architecture and engineering firms in the world.

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