MnDOT inspected the bridge in June 2010 and identified several repairs needed to keep the bridge open to traffic. Watch video of bridge inspection. Those repairs were completed in the summer of 2010. To minimize future repair needs and accompanying traffic closures, MnDOT “posted” the bridge, restricting vehicles over 80,000 pounds from using this river crossing. MnDOT will inspect the bridge on a regular basis and continue to make repairs needed to keep the bridge in service. Inspections performed in 2011 identified no major issues needing repair.
Laws passed by the Minnesota legislature following the I-35W Bridge collapse provide funding for rehabilitation or replacement of certain types of bridges in the state. The Winona Bridge is “fracture critical” by nature of its truss design. The current study is focused on rehabilitating the bridge to ensure its continued structural integrity.
The existing bridge is eligible for the National Register of Historic Places. Federal laws protecting historic structures require that MnDOT study options which would preserve the bridge as long as practical. Various options under study include different combinations of rehabilitation and new construction for sections of the bridge.
A rehabilitation project could range from fairly minimal repairs and painting, to a major overhaul such as disassembling the bridge and rebuilding it with partially new materials. A range of options is under study to identify which types of rehabilitation would provide the needed structural repairs, while also preserving the historic character of the bridge to the greatest extent feasible.
The length of time a project would take is dependent on which option is selected. A minor project might be able to be completed while traffic continues to use the bridge, while a more intensive project could take as long as a new construction project. An important study parameter for major bridge rehabilitation projects is the relationship between cost and time. Engineers must sometimes decide between using costly techniques to accelerate the pace of construction and finish a project more quickly, or using more conventional techniques at lower cost but with greater community disruption. Evaluating and weighing the costs of construction and the costs of community impacts is an important part of this study.
Some types of rehabilitation work could be performed while the bridge continues to carry traffic. Impacts could range from minor inconveniences such as off-peak lane closures for simple construction work, to multi-day complete closures for complicated structural repairs. Certain types of major structural rehabilitation could require complete closure of the bridge for one or more construction seasons. It is possible that a rehabilitation program requiring a lengthy period of complete closure could also include construction of a parallel temporary bridge to maintain traffic. MnDOT is studying this issue closely and is evaluating methods to mitigate closures and keep traffic flowing at this important river crossing.
Currently, extremely heavy vehicles (over 40 tons, the legal highway weight limit) are not allowed to use the bridge. Legal weight limit commercial trucks can continue to use the bridge, but passage of heavier commercial trucks (“permit loads”) would risk damaging it and such loads are forbidden. For most bridges, heavier vehicles are allowed with a permit. The ability of a rehabilitated Winona Bridge to carry heavy vehicles is under study, with the goal that a rehabilitation program will enable the bridge to once again carry heavy commercial “permit load” vehicles.
Historic bridge information
Completed in 1942, the Winona Bridge is eligible for listing on the National Register of Historic Places, established by the National Historic Preservation Act of 1966. Section 106 of the Act requires federal projects to consider historic preservation in planning and decision making. MnDOT, the Federal Highway Administration, and the State Historic Preservation Officer (SHPO) work together to ensure the Section 106 process is followed. In addition, state-level agreements also govern historic preservation considerations.
The feasibility of rehabilitating the existing bridge is a key factor in understanding the project alternatives. Because they must reflect both state and federal regulations and policies, evaluation criteria are being carefully reviewed at all levels. Factors under consideration include the impacts of rehabilitation activities on the historic materials and design of the bridge, the cost of rehabilitation options, the life expectancy of the bridge following rehabilitation activities, and whether rehabilitation can occur without closing the bridge for a significant amount of time.
The character-defining features that make the bridge historically significant are:
- The through-truss design and construction techniques
- The deck truss design and construction
- Architectural design elements used in the concrete piers
These elements of the bridge are the most important to try to preserve in a rehabilitation project.
Decisions regarding the project will be made by MnDOT as the agency responsible for the bridge, in consultation with the Federal Highway Administration. MnDOT will also obtain approval (municipal consent) from the City of Winona for the project as required by state law. MnDOT must also obtain a number of other approvals for the project addressing river navigation, environmental impacts, and land acquisition.
MnDOT is moving forward in a collaborative process involving City and County staff, state and federal permitting agencies, and representatives from the Winona area, to identify and evaluate alternatives, leading to selection of a preferred alternative that best balances the many concerns associated with the project.
The process of identifying options originally looked at both rehabilitation and the potential for building a second (new) bridge on a new alignment, either right next to the existing bridge or at an alternative location such as Huff Street. As the study progressed, much has been learned about environmental and community issues, the historic character of the bridge, and the details of potential rehabilitation needs. While the process may seem lengthy, the critical analysis needed to understand if the bridge can be rehabilitated in a cost-effective manner and the assessment of replacement bridge options are complicated tasks requiring time to ensure that all viewpoints are carefully considered.
MnDOT and project stakeholders have agreed that an additional investment of time was needed to clarify the rehabilitation option goals with the agencies involved, to thoroughly evaluate the condition of the existing bridge, and to identify cost-effective options for rehabilitation that also preserve the historic character of the bridge. This additional investment will pay dividends in project efficiency and user benefits.
I’m concerned about the impact of a four-lane roadway. Is a four-lane bridge needed? Are you taking into account changes in traffic needs due to less driving or smaller vehicles?
To determine the appropriate number of traffic lanes for this river crossing MnDOT examined the amount of traffic which uses the bridge today, the amount of traffic anticipated in the future, and how the traffic needs to move onto and away from the bridge. Existing traffic volumes could be handled with only one lane in each direction. However, MnDOT must also consider anticipated future traffic volumes in order to make responsible decisions about long-term investments in the river crossing. The methods used to estimate future traffic volumes consider historic traffic volumes, projected changes in driving patterns, community changes, technological advances, and modal impacts (i.e. bicycling, walking, and using transit).
Traffic forecasts and analyses of future traffic operations indicate that two lanes will not provide sufficient capacity for future traffic volumes between 4th Street and the river. MnDOT is studying rehabilitation alternatives that would provide increased traffic capacity in this area. One group of alternatives would widen the roadway to four lanes from 4th Street north toward the river, with a transition back to two lanes at the main river spans. These alternatives would keep and rehabilitate the existing main truss structure over the river while reconstructing the approach spans just north of 4th Street Traffic operations analysis indicates that this configuration could accommodate forecast traffic volumes for the foreseeable future (e.g. next 20-25 years).
Another possible group of alternative would rehabilitate the existing bridge without widening the roadway, while also constructing a new two-lane bridge adjacent to the existing structure. This would provide two bridges configured as a “one-way pair” with two lanes of outbound traffic on one bridge and two lanes of inbound traffic on the other bridge.
Analysis of traffic patterns indicates that traffic both approaching and leaving the bridge is dispersed in all directions throughout the City of Winona (see graphic from October 2010 Open House for more detail). The existing road network is expected to accommodate future traffic volumes with relatively minor adjustments at a limited number of intersections.
Will the different alignments change the truck routes through Winona? I’m concerned about more trucks coming through my neighborhood.
Rehabilitation of the existing bridge would not directly affect permanent truck routes in the City of Winona since no changes would be made in bridge alignment. It is possible that short-term changes in truck routing during construction could occur if a temporary bridge for maintenance of traffic is part of the selected alternative.
If a new bridge is part of the project, potential changes to truck routes will be assessed (along with related community impacts) for all alternatives. Changes to truck routes would be determined by the City of Winona and MnDOT. Typically local neighborhood streets are not assigned truck routes due to their limited pavement design. Truck routes must also accommodate the turning radius and width of larger vehicles.
How will traffic access Riverview Drive? Wouldn’t it be easier if vehicles could go directly to Riverview Drive from the bridge?
Analysis of traffic patterns approaching/leaving the Highway 43 bridge show that one-third of the traffic originates or is destined to the area west of Huff Street; the remaining two-thirds of the traffic is coming from/going to the east or the south. Given this analysis, a bridge alignment directed specifically toward Riverview Drive would create a significant detour for the majority of the traffic.
However, access to Riverview Drive, and the port facilities located in this area, remains a critical issue. Options for providing direct access to Riverview Drive from the bridge via an “exit ramp” have been examined but are problematic from an engineering perspective due to clearances required for river navigation and railroad routes parallel to Riverview Drive.
Why were some alignments dismissed?
Study is currently focused on rehabilitation of the existing bridge, which would not require a permanent new river crossing alignment.
Early studies also investigated the potential for a new bridge. A broad range of new bridge location alternatives has been considered since the project began in 2009. Analysis of traffic patterns early in the project found that traffic using the bridge was evenly dispersed geographically through the City, indicating that a centralized bridge location would most effectively serve the majority of the traffic. The Pelzer and Mankato alignments were dismissed largely because of this issue. Other more centralized alignments at Harriet, Washington and Johnson Streets were dismissed due to the potential for significant property impacts as existing street widths were too narrow to accommodate a bridge without significant impacts.
I’m concerned about impacts to my neighborhood, parks, community facilities, etc. How does MnDOT plan to prevent or address impacts?
Regardless of whether a rehabilitation-only option is selected, or a new bridge is part of the solution, MnDOT is evaluating the alternatives based on potential impacts to the community and the environment, as well as how well the alternatives meet the project purpose and need. Broad assessment of potential impacts will be used to select a preferred alternative. Once a preferred alternative is selected, a more detailed analysis will determine how potential impacts can be avoided or minimized. This analysis will be documented in an environmental document and made available for public input prior to project approvals.