S 474
Carrying S 474 over RR
4M SE FRENCHTOWN, Missoula, Montana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: S 474
The S 474 bridge in Missoula, Montana carries S 474 over RR. It was built in 1959, making it 67 years old today. The structure is built primarily of steel and spans 3 sections, stretching 56.0 meters (184 feet) end to end. Daily traffic averages 1,371 vehicles, placing it in the moderately-trafficked tier of Montana bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 4/9, substructure at 6/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order. Its NBI inventory load rating is 22.7 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How S 474 compares
Live comparison across Montana.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1959
- Material
- Steel
- Number of Spans
- 3
- Structure Length
- 56.0 m (184 ft)
- Deck Width
- 8.3 m (27 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 1,371 vehicles/day
- Structure Number
- S00474000+06321
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
S 474 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 S 474 against other structures in Missoula and across Montana. Montana 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 S 474?
S 474 in Missoula, Montana has a deck rating of 5/9, superstructure rating of 4/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is S 474 inspected?
S 474'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 1,371 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. S 474 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 S 474?
S 474 has an NBI inventory load rating of 22.7 metric tons.
Who is responsible for maintaining S 474?
S 474 is owned and maintained by State Highway Agency.
How old is S 474 and does age affect safety?
S 474 was built in 1959, making it 67 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.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.