With growing concerns centered around the deterioration of the Dunklin Street bridge, city staff hopes to begin constructing a replacement bridge in June.
Over the last several years, the city has limited the weight on the bridge and narrowed the lanes to keep vehicles off the "most compromised portions," according to City Engineer David Bange's memorandum to the Jefferson City Public Works and Planning Committee. However, the bridge continues to deteriorate and needs replacing.
"We think it's important, given the condition of the bridge, to move that forward as soon as possible," Bange told the committee Thursday.
The proposed replacement single-span steel girder bridge would be about 90 feet long and 56 feet wide and contain two lanes of traffic. The project includes improving the surrounding corridor and adding bike lanes, a sidewalk and greenway trail.
The street from the bridge to Broadway Street would be 38 feet wide, with a 5-foot wide sidewalk on the western side from Missouri Boulevard to Broadway Street. A greenway trail would be on the eastern side from Missouri Boulevard to Mulberry Street, with the remaining distance to Broadway Street being a 5-foot-wide sidewalk.
The project also includes reducing the vertical curve at Mulberry Street and reconstructing the stormwater system and sanitary sewer, as well as enlarging the Wears Creek sewer interceptor.
The replacement comes with a hefty estimated price tag — $2.9 million — Bange said. Designing the project is estimated to cost about $300,000 of that amount, he added.
The Jefferson City Council approved a $285,521 contract with Bartlett & West in May to design the bridge, as well as other street improvements between Missouri Boulevard and Broadway Street.
The bridge-replacement project is listed under Sales Tax G as a joint project between Jefferson City and Cole County. Bange said they would draft a development agreement with the county to establish the cost share. City staff plans to speak at the Nov. 20 Cole County Commission meeting.
Bange said Bartlett & West would complete the design process in February, with construction possibly beginning in June.
Dunklin Street would be closed for about six months once construction begins. Traffic would be diverted to Whitten Expressway and possibly to Southwest Boulevard, using Broadway and Linden streets.
The city still needs MoDOT's permission to work on portions of its right of way, the memorandum states. The city would also need temporary construction easements to reconstruct driveways and connect to existing parking lots.
In other business, city staff stood firm with its decision to remove a stoplight at the intersection of Industrial and Jaycee drives. City staff permanently removed the stoplight in June after a vehicle struck it.
Schellridge neighborhood residents spoke against removing the light last summer and asked the city to redo a traffic study of the intersection to take school traffic into account.
While the traffic volume has increased slightly at the intersection since 2016, Bange said, it still did not warrant a traffic signal under the Manual on Uniform Traffic Control Device.
City staff upgraded the lights at the intersection to improve visibility, at the residents' suggestion. Schellridge neighborhood resident Paula Johnson said the lights "definitely made a difference."
While she understood "it's not a reality that we're going to get a stoplight back or a roundabout," Johnson said, she appreciated the extra lighting and asked the committee to still consider adding more signage and lowering the speed limit in the area.
The speed limit is 40 miles per hour, and Bange said the majority of drivers either drove the speed limit or were less than five miles over.
As of October, he added, there have not been any reported accidents at the intersection since the stoplight was taken down in June.