Off-System Bridge Study, MDT and MACo logo Bridge Location: Petroleum County

Bridge Location: Petroleum County

Project Overview

The Montana Department of Transportation (MDT) will analyze the condition of our state’s “off-system” bridges, which are critical for moving goods and people, and represent one of Montana’s most significant challenges.

There are more than 2,000 off-system bridges in Montana, many have served their useful service life and are in disrepair, or load posted, which can greatly impact local and regional economies and our ability to easily move around.

The project, called the Off-System Bridge Study and Implementation Plan, will evaluate the current condition of off-system bridges, and develop a strategic implementation plan and processes for future repairs or replacement options for bridge owners (i.e., county governments). Due to limitations in funding, not all bridges can be addressed. The study and implementation plan will be the basis of a strategic plan for bridge owners to put infrastructure funding to work in the most effective manner possible.

Project Objectives:

  • Identify potential quick fixes for load posted bridges and bridges in poor condition. This would allow some bridges to remain in service until they are permanently repaired or replaced.
  • Determine a list of prioritized bridges and future candidate projects for off-system bridge owners to implement.
  • Identify funding opportunities for owners to partner with MDT to support bridge repair or replacement projects.
  • Engage and inform the public, counties, and other stakeholders throughout the process.

MDT values its partnership with the Montana Association of Counties (MACo) to support county bridge priorities and provide updated information about MDT’s Off-System Bridge Study and Implementation Plan. MDT is committed to continuing our work with MACo and counties to ensure the off-system bridges are safe, resilient, and will provide an economical and reliable transportation system now and for future generations.

Project Updates

Replacing Off-System Bridges with SB 536 Funds
The Off-System Bridge Strike Team, comprised of MDT and MACo, has initially selected six bridges from six different counties for replacement using Senate Bill (SB) 536 funds. MDT will administer these projects to leverage future federal funding opportunities. These six bridge replacements exceed the goal of programming five bridge replacements by the end of 2023 under the Off-System Bridge Study and Implementation Plan.

Bridges considered for replacement included:

  • Load posted or closed bridges.
  • County-priority bridges.
  • Bridges in poor condition based on their Off-System Bridge Priority Score, as derived from the MDT Off-System Bridge Study and Implementation Plan.

Bridges removed from consideration included:

  • Bridges funded by other mechanisms such as Federal Emergency Management Association (FEMA), Montana Coal Endowment Program (MCEP), and MDT Bridge Off-System.
  • Bridges with unforeseen factors such as excessive costs.

MDT contacted each of the respective counties and verified their interest in having qualified bridges replaced. MDT also verified the counties did not already have plans or separate funding to replace those bridges.

The Strike Team also selected four other bridges for replacement through County-led efforts using SB 536 funds. These selections were directly tied to bridge closures and the need to react quickly. Additional MDT-led bridge replacements are forthcoming over the coming months, using the same prioritization/selection process.

Temporary Off-System Bridge Repairs

During the first phase of this project, MDT and its consultant team made up of HDR and Stahly Engineering, reviewed the off-system bridges as well as identified a list of candidate bridges which could potentially benefit from temporary repairs as part of bridge rehabilitation strategies.

The team looked for opportunities to perform temporary repairs for bridges currently load posted or subjected to restricted use and used the following steps to develop the list:

  • First, the team reviewed the set of bridges identified by the counties as priorities.
  • Next, the team identified all the bridges scored as high-priority based on the Off-System Bridge evaluation and not already identified as repair candidates above.
  • Finally, the team included the current load posted bridges not identified as repair candidates in both items above.

MDT selected bridges that could benefit from repair options that have been used successfully in the past to address similar issues for other bridges. Repairs that would require highly specialized equipment or contractors were not selected. Repairs may include adding a curb to divert traffic away from an outside beam line, replacing the timber decking, adding an additional beam next to an existing beam, or repairing timber piles.

These repairs are not long-lasting solutions. Rather, the repairs would be relatively quick and temporary fixes which could reduce or eliminate load restrictions, address a serious condition issue, and allow a bridge to remain in service while planning for a long-term rehabilitation or replacement option.

MDT requires a post-repair inspection and updated bridge load rating after a repair is completed and before a load-posting or other restrictions can be modified or removed. A repair does not always result in a reduced or removed posting.

If a county, through an engineer, has cost effective ideas for a repair, they are encouraged to contact MDT to request SB 536 funding to contribute towards repairs of off-system bridges.

Next Steps
In 2024, MDT will continue to replace off-system bridges by:

  • Initiating a bridge replacement project for each of these bridges individually.
  • Determining which of these bridge replacement projects will be developed by consultants, MDT staff, or alternative contracting.
  • Assigning MDT Design Project Manager(s) and begin project development.

There are nearly 50 bridges from multiple counties with temporary off-system bridge repairs in various stages of completion. This project will continue to:

  • Review load restricted or closed bridges to determine if a temporary repair is feasible and warranted.
  • Identify additional bridges that would benefit from temporary repairs.
  • Reach agreements on repairs that meet present and future funding opportunities.
  • Engage the counties and solicit input from stakeholders.

Interactive Map

An interactive online map was developed to assist bridge owners and others with locating and understanding the condition of off-system bridges throughout Montana. The public is encouraged to utilize this interactive map, which can be found at the following link: MDT Off System Bridges Public Dashboard.

Stay Informed, Stay Involved

In addition to stakeholder meetings, the project team will communicate with you using direct mail, social and traditional media outreach, and a project website, among other tools.

New project information will be posted on this website as it becomes available, but you can request to be added to our mailing list or submit a comment electronically. To send us your U.S. mail or email address or to submit a comment; MDT’s Online Comment Form. Please note that your comments are for the Off System Bridge Study, UPN 10115. Thank you!

UPN 10115