Bridge Type Selection
The Bridge Type Selection process concluded in Dec. 2006 with the Executive Bridge Type Selection Committee’s selection of the Three-Tower Cable-Stayed bridge type for the Downtown Bridge and the Median-Tower, Cable-Stayed Center Cable bridge type for the East End Bridge. The selection ended an 18-month process that included cost and preliminary engineering analysis of several bridge type alternatives for both bridge locations and considerable public input.
Officials on both sides of the river committed to a bridge type selection process that entailed sharing concepts with the community as they were developed and offering them several opportunities to provide feedback. Taking into consideration public input, cost and engineering feasibility, an executive oversight committee with bi-state representation ultimately selected the designs.
Both bridge design teams began the Bridge Type Selection Process in early 2005. At each stage of the process, the design teams presented their work for comments at public meetings and at meetings with the project’s advisory teams.
In Nov. 2006, the Executive Bridge Type Selection Committee requested additional public input on the three final bridge types for both the Downtown and East End Bridge locations. The committee considered that feedback in an effort to choose bridge types that were consistent with the communities’ character and wishes. The committee selected the final bridge types in Dec. 2006, voting unanimously for both the Three-Tower Cable-Stayed bridge type for the Downtown Bridge and the Median-Tower, Cable-Stayed Center Cables bridge type for the East End Bridge.
A team led by Michael Baker Jr., Inc., designed concepts for the new Downtown Bridge and a team led by Parsons Brinckerhoff Quade and Douglas designed concepts for the East End Bridge. Both teams’ work was managed by the Bi-State Management Team, consisting of representatives from the Kentucky Transportation Cabinet, the Indiana Department of Transportation and the Federal Highway Administration.
STEP 1: DESIGN GUIDELINES
The Bridge Type Selection Process for the new Downtown and East End Bridges followed a four-step process, as follows:
- Design guidelines development
- Bridge type concepts
- Bridge type alternatives
- Bridge type selection
In Step One, the two bridge design teams worked with the public to establish design guidelines for the new Downtown and East End Bridges. These guidelines provided a framework within which stakeholders, the general public and design engineers collaborated throughout the Bridge Type Selection Process.
Guidelines ensured the bridge architects and designers had all the information they needed to begin brainstorming on what would be appropriate in each of the two sites where new bridges will be built. In Step One, the design teams presented to the public a list of design parameters for the two bridges. Parameters are criteria that were set either through codes or standards or by previous studies such as the Final Environmental Impact Statement. Parameters included things such as span lengths, span widths, pier arrangements and cost budgets – these are some of the factors that helped determine the types of bridges that could be built.
Four bridge types – truss, cable-stayed, arch and box girder – were determined as feasible at the two bridge locations, both of which call for long-span structures.
Research and public involvement efforts in this step provided the bridge design teams with information on the cultural characteristics of each area. Context sensitive considerations included the type of architecture prevalent in surrounding buildings and neighborhoods and historical features that could be reflected in the bridge designs. Discussions with stakeholder groups and the public included environmental and historical characteristics that might be reflected in the bridge designs.
With design guidelines that were established, public feedback on aesthetic considerations was weighed carefully as the Ohio River Bridges Project moved through the Bridge Type Selection Process.
STEP 2: BRIDGE CONCEPTS
AAT (Area Advisory Team), BSMT (Bi-State Management Team), RAC (Regional Advisory Committee)
In Step Two of the Bridge Type Selection Process, the East End Bridge and Downtown Bridge design teams and the community examined a number of different bridge concepts for each bridge location. The four long-span bridge types that were feasible in these locations were truss, cable-stayed, arch and box girder.
There were a number of design parameters required by the Record of Decision and various local, state and national design codes and standards. These parameters included details like span length and vertical clearance.
Each bridge has a team of designers who developed general bridge type concepts during this step, which was used to solicit feedback and preferences on overall aesthetics. The concepts were presented to the project advisory teams and then to the public at a series of open houses.
Visualization tools and computer imaging showed each of the various bridge type concepts in context at each location. Lifelike digital renderings of the downtown area with existing bridges and parks showed a concept of the new bridge next to the Kennedy. This allowed people to see what the combination might look like. The community also saw what a bridge linking Prospect and Utica might look like. Various perspectives of each bridge showed what a new bridge would look like from the river, the shoreline and from nearby businesses or houses.
After the information from Step Two was analyzed, Steps Three and Four of the Bridge Type Selection Process resulted in more detailed bridge type alternatives designed to meet the project parameters and design guidelines while being consistent with the general aesthetic preferences that were gathered from the community.
STEP 3: BRIDGE ALTERNATIVES
In Step Three of the Bridge Type Selection Process, the architects and engineers for the bridge design teams developed detailed renderings of design alternatives for each new bridge location, based on the design guidelines and concept preferences established in Steps One and Two.
The Area Advisory Teams (AAT) and Regional Advisory Committee (RAC) provided input on the bridge type alternatives through the use of preference polling similar to the process used in Step Two.
Input from all the advisory teams was used throughout Step Three to refine the draft alternatives. Following review and approval by the Bi-State Management Team, the refined alternatives were shown to the public at the Step Three Open Houses. Open house attendees provided feedback and asked questions.
Following the Step Three Open Houses, the design teams developed a set of bridge type alternatives for evaluation and refinement in Step Four – the final phase of the Bridge Type Selection Process.
STEP 4: FINAL BRIDGE TYPE
Step Four of the Bridge Type Selection Process entailed narrowing the list of alternatives to three final bridge types. The design teams developed a comprehensive assessment of each of the final bridge types and presented all of the input received from the advisory teams and the public to the Executive Bridge Selection Committee, made up of representatives from Indiana and Kentucky. The Executive Bridge Type Selection Committee decided on the final bridge type at each location based on the assessments from the design teams and considerable public input on the three final bridge types for both the Downtown and East End Bridges.
The design of the final bridge type alternatives was coordinated with the adjacent approach sections to ensure smooth transitions to the new interchanges on each side of the river. Cost estimates for each alternative were carefully reviewed and finalized, and preliminary Coast Guard approval of details such as pier location for each alternative was obtained.
There were advisory team meetings in this step to inform the members of the recommended list of bridge type alternatives and to solicit feedback. All of the information developed through the four-step Bridge Type Selection Process and all of the input received from the advisory teams and the public was presented to the Executive Bridge Type Selection Committee for its consideration in selecting the final bridge types.
Both states were committed to the principles of Context Sensitive Design, and to working closely with the public to ensure their involvement in the bridge type selection and to develop alternatives that reflected the character of the community and the surrounding environments.
The project moved into a 24-month design process upon the selection of the Final Bridge Types in December 2006.
FINAL BRIDGE TYPE – DOWNTOWN
THREE-TOWER CABLE-STAYED BRIDGE TYPE
The Three-Tower Cable-Stayed Bridge Type features three low-height towers with cables arranged in a simple, harp formation. The design blends with the current Kennedy Bridge and skylines of both Louisville and Clarksville/Jeffersonville to give the waterfront an attractive new structure that fits with its landscape to provide an open, welcome approach to Indiana.
The bridge type meets engineering, navigation and safety criteria established for the location and is considered a low-maintenance bridge type. The three pairs of concrete towers and bridge deck are supported on steel beams. The steel cables are enclosed in a plastic pipe. The center towers rise 210 feet above the bridge deck with the sets of outside towers lower at 125 feet.
Navigation channels for river traffic meet U.S. Coast Guard requirements with a pair of 750-foot water ways on either side of the center tower. The tower is positioned to the south of the river’s center as a result of the navigation requirements.
The Three-Tower Cable-Stayed Bridge Type was selected after a thorough public involvement process that included feedback from advisory teams as well as the general public during the development of guidelines, concepts, alternatives and ultimately the final bridge type.
FINAL BRIDGE TYPE – EAST END BRIDGE
MEDIAN-TOWER CABLE-STAYED CENTER CABLES
The Median-Tower Cable-Stayed Center Cables Bridge Type features two needle towers with cables running from the towers to the median of the bridge deck. The design provides motorists, pedestrians and cyclists with unobstructed views of the surrounding landscape looking outward from the bridge deck and provides the surrounding area with a visually transparent structure to blend with the area.
The bridge type is a low maintenance bridge type that meets all engineering, navigation and safety criteria. Two concrete needle towers rise 300 feet above the water and support the superstructure with steel and concrete box girders and concrete deck. The sheathed steel strand cables extend from the tower to the bridge deck median in a fan formation.
The navigation channel for river traffic meets U.S. Coast Guard requirements with a single 900-foot wide waterway in the center span of the bridge.
The Median-Tower Cable-Stayed Center Cables Bridge Type was selected after a thorough public involvement process that included feedback from advisory teams as well as the general public during the development of guidelines, concepts, alternatives and ultimately the final bridge type.
DOWNTOWN BRIDGE DESIGN ALTERNATIVES
The design team for the Downtown Bridge started with 31 concepts for bridge types. After considering public input, engineering feasibility and cost, the number was whittled to 6; then narrowed again to 3.
Recommended Alternative 3 – The Three-Span Arch design has three sets of inclined arch ribs, connected by horizontal bracing. One unique feature of this design is the arch form, which extends down to water level. The vertical support hangers attach to the outside of the deck superstructure.
The top perspective shows a view of the bridge from the Jeffersonville Park. The bottom view presents a view from Waterfront Park on the Louisville side of the river.
The image below is a view of the underside of the bridge from Waterfront Park in Louisville.
You can view each alternative from the perspective of a driver crossing the bridge.
The images below represent what the alternatives may look like at night. The aesthetic lighting has not been determined yet. These images represent one possible scenario.
EAST END BRIDGE DESIGN ALTERNATIVES
The design team for the East End Bridge started with 15 different concepts for bridge types. After considering public input, engineering feasibility and cost, that number was whittled to 6; then narrowed again to 3.
Recommended Alternative 1 – Diamond-Tower Cable-Stayed
This alternative features two diamond-shaped support towers with cables that extend diagonally from either side of both towers and attach to the outside of the deck.
The left image shows the pedestrian walkway on the bridge and what it may look like walking across. The image on the right depicts a perspective that boaters may have traveling down the river. It gives an idea of what the underside of the bridge might look like.
You can view each alternative from the perspective of a driver crossing the bridge.
The image below represents what the alternative may look like at night. The aesthetic lighting has not been determined yet. This image represents one possible scenario.