NW SAMMAMISH ROAD
Carrying NW SAMMAMISH ROAD over TRIBUTARY 170
0.5 M WEST OF SR-900, King, Washington
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
NW SAMMAMISH ROAD in King, Washington sits above 97% of rated Washington bridges on inventory load rating (81 t), while its 2008 build year is earlier than 12% of King's recorded-year cohort (1,238 bridges).
NW SAMMAMISH ROAD in King, Washington is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2008, it carries 1 rated component on the inspecting agency's 0-9 scale, and its weakest reported component scores 8. 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:088029000000000
POST-2000 · CONCRETE · SINGLE-SPAN · CULVERT-LED · HEAVY-ADT · HEAVY-LOAD · CAT-GOOD
- POST-2000 2000+
- CONCRETE Concrete
- SINGLE-SPAN Single span
- CULVERT-LED Culvert-led
- HEAVY-ADT Heavy ADT
- HEAVY-LOAD Heavy 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: NW SAMMAMISH ROAD
The NW SAMMAMISH ROAD bridge in King, Washington carries NW SAMMAMISH ROAD over TRIBUTARY 170. It was built in 2008, making it 18 years old today. The structure is built primarily of concrete and spans 1 section, stretching 7.9 meters (26 feet) end to end. Daily traffic averages 13,500 vehicles, placing it in the heavily-trafficked tier of Washington bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show culvert at 8/9. The weakest component sits in good condition. No reported major component scores in the Poor range under the current federal condition thresholds.
How NW SAMMAMISH ROAD compares
Age against the county: built in 2008, earlier than 144 of King's 1,238 bridges with a recorded construction year (12%), against a county median build year of 1972. This is one of the newer structures in its county.
Live comparison across Washington bridges with a recorded inventory load rating (8,455 of 8,474 rated).
NW SAMMAMISH ROAD vs every rated Washington bridge
Inventory load rating (metric tons), FHWA NBI, this state
81 Top 3% higher than 97% 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.
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
- 2008
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 7.9 m (26 ft)
- Deck Width
- 18.9 m (62 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 13,500 vehicles/day
- Structure Number
- 088029000000000
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 NW SAMMAMISH ROAD 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 NW SAMMAMISH ROAD 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 NW SAMMAMISH ROAD?
NW SAMMAMISH ROAD in King, Washington on the FHWA's 0–9 scale.
How often is NW SAMMAMISH ROAD inspected?
NW SAMMAMISH ROAD'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 13,500 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NW SAMMAMISH ROAD 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 NW SAMMAMISH ROAD?
NW SAMMAMISH ROAD has an NBI inventory load rating of 80.7 metric tons.
Who is responsible for maintaining NW SAMMAMISH ROAD?
NW SAMMAMISH ROAD is owned and maintained by City/Municipal Highway Agency.
How old is NW SAMMAMISH ROAD and does age affect safety?
NW SAMMAMISH ROAD was built in 2008, making it 18 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.