The Oregon Street bridge could be replaced with a “high-level fixed” structure that would provide nearly three times the current clearance over the water, a Department of Transportation official said.
This option, which would eliminate the span’s drawbridge, is just one of a wide range of alternatives that are under study and that are scheduled to be shown at a public hearing Oct. 13 at the Oshkosh Seniors Center on Campbell Road starting at 5 p.m.
Rehabilitation or replacement of the bridge is years in future, starting no sooner than 2022. But the project could have implications for waterfront development, depending on which alternative is chosen.
One of the possible alignments would move the bridge to the west, which could have a “substantial impact” on the proposed $55 million project known as the Morgan District, said Allen Davis, the city’s director of community development. Other alternatives could affect City Center, he warned.
Bill Bertrand, the DOT project manager, said the possible new alignments “generally run close to and along [the]west side of the existing bridge.”
There are several benefits to building a new structure, he said. If this approach is adopted, “we can minimize impacts to development in [the] northeast quadrant of the bridge and also minimize the closure time of [the] bridge under a replacement scenario.”
While Bertrand said the bridge is safe to use, he also pointed to a long list of problems. In an email, he described the following issues:
“1) Bridge Deficiencies
- Movable bridge machinery shows signs of wear and corrosion and needs replacement
- Deterioration of tack welds and steel plates require repair
- Cracking and spalling on concrete surfaces of bridge piers
- Sidewalks are less than the standard widths
- Approach spans and sidewalks need repair
- Vertical profiles of roadway approaches are below current design standards
“2) Bridge Operations
- Bridge tender has poor visibility to monitor vehicles and pedestrians when raising the bridge
- Low vertical clearance – bridge had 400 more openings in 2015 than adjacent bridges
- Vehicle crash rate is above statewide average for similar roadways
- Bridge railing of bascule [drawbridge]span is offset into sidewalk, creating potential hazards for pedestrians and bicyclists
- Narrow lane and sidewalk widths do not provide safe bicycle accommodations
- Riverwalk pedestrians and bicycle traffic are required to cross road at grade (cannot cross under bridge), creating a mid-block at-grade pedestrian crossing
- Steel grid panels in deck are offset and present a hazard to bicyclists
- Approach sidewalks have settled and present a tripping hazard”
Despite these issues, one alternative is to forego rebuilding and another is to rehabilitate the existing structure. There are “multiple bridge replacement alternatives that could either be on the existing alignment or on a new alignment,” Bertrand said.
His schedule calls for getting environmental approvals by late 2017 for the whichever alternative is deemed “preferred.”
If a decision is made to get rid of the existing drawbridge, the design considerations would include matching the clearance height over the river with that of the Lake Butte des Morts bridge on I-41. That height is 23 feet, Bertrand said, compared to 8 or 9 feet under the existing bridge when it is closed.
“We will need to validate this clearance with the U.S. Coast Guard and other agencies if that alternative moves forward for more detailed evaluation,” Bertrand added.
Moving the Oregon Street bridge to the west would minimize traffic disruption but could have a substantial impact on the Morgan District project. Photo by Miles Maguire.