IRR BIA RTE 18
Carrying IRR BIA RTE 18 over PINE CREEK
1.5KM S MARTIN FERRY BD., Humboldt, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IRR BIA RTE 18 in Humboldt, California is rated Fair in the FHWA's 2024 National Bridge Inventory.
Built in 1977, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 5. The lowest applicable rating sets the federal condition category, so this Fair 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 CA:00000000000J140
INTERSTATE-ERA · PRESTRESS · MULTI-SPAN · SUB-LED · TRACE-ADT · STANDARD-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- MULTI-SPAN 2 spans
- SUB-LED Substructure-led
- TRACE-ADT Trace ADT
- STANDARD-LOAD Standard load
- CAT-FAIR Fair
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: IRR BIA RTE 18
The IRR BIA RTE 18 bridge in Humboldt, California carries IRR BIA RTE 18 over PINE CREEK. It was built in 1977, making it 49 years old today. The structure is built primarily of prestressed concrete and spans 2 sections, stretching 37.3 meters (122 feet) end to end. Daily traffic averages 40 vehicles, placing it in the lower-traffic tier of California bridges. It is owned and maintained by Bureau of Indian Affairs.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 6/9, substructure at 5/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How IRR BIA RTE 18 compares
Age against the county: built in 1977, earlier than 101 of Humboldt's 396 bridges with a recorded construction year (26%), against a county median build year of 1965. This is one of the newer structures in its county.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
IRR BIA RTE 18 vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
25 Top 78% higher than 22% of 25,538 bridges
rated California 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.
Humboldt inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 396 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
- 1977
- Material
- Prestressed Concrete
- Number of Spans
- 2
- Structure Length
- 37.3 m (122 ft)
- Deck Width
- 7.3 m (24 ft)
- Owner
- Bureau of Indian Affairs
- Avg Daily Traffic
- 40 vehicles/day
- Structure Number
- 00000000000J140
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • 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 fair condition (5/9), with minor deterioration that may require routine maintenance.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether IRR BIA RTE 18 is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare IRR BIA RTE 18 against other structures in Humboldt and across California. California 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 IRR BIA RTE 18?
IRR BIA RTE 18 in Humboldt, California has a deck rating of 7/9, superstructure rating of 6/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is IRR BIA RTE 18 inspected?
IRR BIA RTE 18'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 40 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IRR BIA RTE 18 is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for IRR BIA RTE 18?
IRR BIA RTE 18 has an NBI inventory load rating of 24.5 metric tons.
Who is responsible for maintaining IRR BIA RTE 18?
IRR BIA RTE 18 is owned and maintained by Bureau of Indian Affairs.
How old is IRR BIA RTE 18 and does age affect safety?
IRR BIA RTE 18 was built in 1977, making it 49 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.
Share this inspection record
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.