USFS RTE 3458
Carrying USFS RTE 3458 over CARP RIVER
3 MI N BURMA ROAD, Mackinac, Michigan
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
USFS RTE 3458 in Mackinac, Michigan sits above 2% of rated Michigan bridges on inventory load rating (11 t), while its 1955 build year is earlier than 75% of Mackinac's recorded-year cohort (63 bridges).
USFS RTE 3458 in Mackinac, Michigan is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1955, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure MI:091005000001071
INTERSTATE-ERA · TIMBER · MULTI-SPAN · SUB-LED · LOCAL-ADT · LIGHT-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- TIMBER Wood or timber
- MULTI-SPAN 2 spans
- SUB-LED Substructure-led
- LOCAL-ADT Local ADT
- LIGHT-LOAD Light load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: USFS RTE 3458
The USFS RTE 3458 bridge in Mackinac, Michigan carries USFS RTE 3458 over CARP RIVER. It was built in 1955, making it 71 years old today. The structure is built primarily of wood or timber and spans 2 sections, stretching 14.8 meters (49 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of Michigan bridges. It is owned and maintained by U.S. Forest Service.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 6/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed.
How USFS RTE 3458 compares
Age against the county: built in 1955, earlier than 47 of Mackinac's 63 bridges with a recorded construction year (75%), against a county median build year of 1963. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Michigan bridges with a recorded inventory load rating (11,366 of 11,371 rated).
USFS RTE 3458 vs every rated Michigan bridge
Inventory load rating (metric tons), FHWA NBI, this state
11 Top 98% higher than 2% of 11,366 bridges
rated Michigan bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Mackinac inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 63 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1955
- Material
- Wood or Timber
- Number of Spans
- 2
- Structure Length
- 14.8 m (49 ft)
- Deck Width
- 4.5 m (15 ft)
- Owner
- U.S. Forest Service
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 091005000001071
Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • The superstructure (beams and supports above the deck) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
USFS RTE 3458 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare USFS RTE 3458 against other structures in Mackinac and across Michigan. Michigan bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for USFS RTE 3458?
USFS RTE 3458 in Mackinac, Michigan has a deck rating of 5/9, superstructure rating of 6/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is USFS RTE 3458 inspected?
USFS RTE 3458's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. USFS RTE 3458 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for USFS RTE 3458?
USFS RTE 3458 has an NBI inventory load rating of 11.3 metric tons.
Who is responsible for maintaining USFS RTE 3458?
USFS RTE 3458 is owned and maintained by U.S. Forest Service.
How old is USFS RTE 3458 and does age affect safety?
USFS RTE 3458 was built in 1955, making it 71 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
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Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.