550TH RD
Carrying 550TH RD over COATES BR
S 1 T 31 N R 24 W, Polk, Missouri
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
550TH RD in Polk, Missouri sits above 55% of rated Missouri bridges on inventory load rating (34 t), while its 2009 build year is earlier than 18% of Polk's recorded-year cohort (185 bridges).
550TH RD in Polk, Missouri is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2009, it carries 3 rated components 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 MO:33053
POST-2000 · PRESTRESS · SINGLE-SPAN · SUB-LED · TRACE-ADT · STANDARD-LOAD · CAT-GOOD
- POST-2000 2000+
- PRESTRESS Prestressed concrete
- SINGLE-SPAN Single span
- SUB-LED Substructure-led
- TRACE-ADT Trace ADT
- STANDARD-LOAD Standard 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: 550TH RD
The 550TH RD bridge in Polk, Missouri carries 550TH RD over COATES BR. It was built in 2009, making it 17 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 21.3 meters (70 feet) end to end. Daily traffic averages 20 vehicles, placing it in the lower-traffic tier of Missouri bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 9/9, superstructure at 9/9, substructure at 8/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How 550TH RD compares
Age against the county: built in 2009, earlier than 34 of Polk's 185 bridges with a recorded construction year (18%), against a county median build year of 1972. This is one of the newer structures in its county.
Live comparison across Missouri bridges with a recorded inventory load rating (24,616 of 24,618 rated).
550TH RD vs every rated Missouri bridge
Inventory load rating (metric tons), FHWA NBI, this state
34 Top 45% higher than 55% of 24,616 bridges
rated Missouri 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.
Polk inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 185 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
- 2009
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 21.3 m (70 ft)
- Deck Width
- 7.4 m (24 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 20 vehicles/day
- Structure Number
- 33053
Condition Analysis
- • At 9/9, the deck (driving surface) is in good shape and shows no significant wear.
- • The superstructure (beams and supports above the deck) rates good at 9/9, with no significant deterioration on file.
- • The substructure (piers and abutments) is in good condition (8/9), showing no significant deterioration.
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 550TH RD 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 550TH RD against other structures in Polk and across Missouri. Missouri 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 550TH RD?
550TH RD in Polk, Missouri has a deck rating of 9/9, superstructure rating of 9/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is 550TH RD inspected?
550TH RD'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 20 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 550TH RD 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 550TH RD?
550TH RD has an NBI inventory load rating of 34.2 metric tons.
Who is responsible for maintaining 550TH RD?
550TH RD is owned and maintained by County Highway Agency.
How old is 550TH RD and does age affect safety?
550TH RD was built in 2009, making it 17 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.