I-405
Carrying I-405 over 115th AVE NE & TRAIL
0.2 N JCT SR 520, King, Washington
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
I-405 in King, Washington sits above 6% of rated Washington bridges on inventory load rating (15 t), while its 1965 build year is earlier than 68% of King's recorded-year cohort (1,238 bridges).
I-405 in King, Washington is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1965, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good 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 WA:0007742A0000000
INTERSTATE-ERA · PRESTRESS · LONG-SPAN-RUN · TIED-CTRL · HEAVY-ADT · LIGHT-LOAD · CAT-GOOD
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- LONG-SPAN-RUN 4 spans
- TIED-CTRL Tied control
- HEAVY-ADT Heavy ADT
- LIGHT-LOAD Light load
- CAT-GOOD Good
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: I-405
The I-405 bridge in King, Washington carries I-405 over 115th AVE NE & TRAIL. It was built in 1965, making it 61 years old today. It was last reconstructed in 1993, extending its service life. The structure is built primarily of prestressed concrete continuous and spans 4 sections, stretching 90.2 meters (296 feet) end to end. Daily traffic averages 65,986 vehicles, placing it in the heavily-trafficked tier of Washington bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. None of this bridge's reported major components fall into the Poor condition range.
How I-405 compares
Age against the county: built in 1965, earlier than 841 of King's 1,238 bridges with a recorded construction year (68%), against a county median build year of 1972. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Washington bridges with a recorded inventory load rating (8,455 of 8,474 rated).
I-405 vs every rated Washington bridge
Inventory load rating (metric tons), FHWA NBI, this state
15 Top 94% higher than 6% of 8,455 bridges
rated Washington 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.
King inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 1,238 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
- 1965
- Last Reconstructed
- 1993
- Material
- Prestressed Concrete Continuous
- Number of Spans
- 4
- Structure Length
- 90.2 m (296 ft)
- Deck Width
- 25.3 m (83 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 65,986 vehicles/day
- Structure Number
- 0007742A0000000
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 I-405 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 I-405 against other structures in King and across Washington. Washington 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 I-405?
I-405 in King, Washington has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is I-405 inspected?
I-405'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 65,986 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. I-405 is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for I-405?
I-405 has an NBI inventory load rating of 14.6 metric tons.
Who is responsible for maintaining I-405?
I-405 is owned and maintained by State Highway Agency.
How old is I-405 and does age affect safety?
I-405 was built in 1965, making it 61 years old and last reconstructed in 1993.
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.