The North Dakota Department of Transportation has begun an engineering and feasibility study for replacing the Grant Marsh Bridge.
That bridge – on I-94 – spans the Missouri River between Bismarck and Mandan.
Michael Johnson is the Urban Engineer at DOT, and is the project manager for the study. Johnson said over the past 10 years or so, DOT has had to do a number of minor repairs to extend the life of the bridge. And that prompted the study.
"The thought process was, 'This is a large bridge — it spans a major river,'" Johnson said. "So the potential replacement that will be needed at some point in time will take a lot of work, a lot of effort."
Johnson said the study will happen over the next 18 months or so.
"The determination will be made, when that study's complete — are we ready at this point in time to move into the next phase, which would be proceeding toward an environmental document, and some preliminary design work," Johnson said. "Or — do we have enough information from this study to help us lay future groundwork and future plans on timing, and lining things up for potential funding as well."
Johnson said part of that study will also look at development of alternatives – what type of bridge, bridge alignment and placement, and necessary improvements to I-94 around it. He said comments from an earlier public meeting will be taken into account.
Johnson said the plan is to have another public meeting – probably this winter.
"Hopefully, at that meeting, we'll be able to bring some early concepts to the public for their thoughts and comments," Johnson said. "It will be through that process that we can start to get an idea as to what some preliminary costs would be."