The LPI makeover: SNBI, CCRs and what it means for you?
By: Dave Conkel, State Aid Bridge Engineer, Moises Dimaculangan, State Aid Bridge Load Rating & Permitting Engineer, and Jerilyn Swenson, State Aid Bridge Program Engineer
In the Spring of 2025, we began transitioning to the new Specifications for the National Bridge Inventory (SNBI) bridge inspection criteria, with full implementation anticipated by 2028. The SNBI introduces several changes, including the addition of Component Condition Ratings (CCRs)—formerly referred to as National Bridge Inventory Condition Codes (NBIs)—as well as new inspection criteria and coding requirements.
These updates require revisions to the Local Planning Index (LPI) spreadsheet manual calculator and MnDOT’s internal program. Recall that these LPI tools were developed to help local agencies manage their bridge inventory. If a bridge meets a specific LPI threshold score based on various factors such as condition structure type, scour, load rating, and more or has deficiencies in hydraulics, bridge width or geometry, it becomes eligible for federal and/or state bridge funding for removal, rehabilitation or replacement.
MnDOT is currently under contract with Collins Engineers Inc. to develop an updated LPI calculator for bridges on the local system using SNBI data. This update is being guided by a subcommittee consisting of several County Engineer Bridge Committee members, local bridge consultants familiar with the old LPI logic, and select MnDOT Bridge Inventory Management Unit personnel. These individuals are closely involved in reprogramming the logic to accurately read live SNBI data from SIMS and to generate an updated LPI scores on demand.
The updated LPI will be referred to as the LPI (SNBI), and the underlying emphasis will remain as a tool to prioritize bridges for funding based on operational risk. This approach aligns with FHWA’s intent to apply performance and risk-based measures to improve the management of our local transportation network.
Transition period to LPI (SNBI) - items to note:
Please note the term “legacy” refers to data obtained prior to the start of SNBI implementation or spring of 2025.
- New bridges added to the inventory
These bridges will not have an LPI calculated, as they lack legacy data required for the current LPI calculation. State Aid does not plan to manually calculate LPI scores for these bridges, given their good structural condition. However, after the full implementation of SNBI, these bridges will start to receive an auto LPI (SNBI) score based on the new implemented SNBI data starting in 2028 and beyond. - “Lost” bridges added to the inventory
These are bridges (mostly culverts) that have been in operation but were not previously included in the local bridge inventory. Most of these will not have an associated LPI score. If your inspection reveals it’s in poor condition and/or the load rating is low or requires posting and would like an LPI score to substantiate funding eligibility, please contact the State Aid Bridge Office. Otherwise, these bridges will not be issued a LPI score until the SNBI is fully implemented. - All bridges with changed conditions
If a bridge’s condition has changed and you believe the LPI score should be updated to substantiate funding eligibility, please contact the State Aid Bridge Office to request a manual reevaluation. - Existing online BRIM tools and reports (BRIM report for locals)
The online BRIM report continues to reference legacy data, along with live inspection and inventory items that remain synched with SNBI data—such as NBI (CCR) Deck, Superstructure, Substructure, Culvert and Channel Condition ratings. However, other important items—such as load rating, scour, ADT, detour, waterway adequacy, deck geometry, and approach alignment—are not synced with SNBI. As a result, these legacy items were frozen as of spring 2025 and will stay fixed until SNBI is fully implemented.- For most of the bridges, the LPI score generated in the BRIM report remains fairly accurate. However, if you have a bridge scheduled for rehabilitation or replacement in the near future and its LPI score is slightly above 60 (making it ineligible for funding), please feel free to request a manual LPI recalculation from State Aid Bridge.
The MCEA Bridge Committee and the LPI (SNBI) Subcommittee will continue to provide updates as we approach full SNBI implementation. Understandably, questions might arise—such as, "what if my previous LPI score warranted bridge funding, but the updated LPI (SNBI) score suggests differently, based on the new established LPI (SNBI) thresholds and criteria? In general, bridges included in your 5-year Capital Improvement Plan that met funding eligibility under the previous LPI criterial will remain eligible, regardless of their updated LPI (SNBI) score or the new criteria. We will make sure you don’t lose funding potential for these situations. But our goal is to transition to the new LPI (SNBI) seamlessly and without major disparities between the old LPI and new LPI (SNBI). Wish us luck!
If you have any concerns or questions, please reach out to our MCEA Bridge Committee Chair, Rachel Gregg (greggr@stlouiscountymn.gov); our Co-Chair, Brian Pogodzinski (brian.pogodzinski@co.houston.mn.us), or Jerilyn Swenson (jerilyn.swenson@state.mn.us), Dave Conkel (dave.conkel@state.mn.us) or Moises Dimaculangan (moises.dimaculangan@state.mn.us).