170 ST
Carrying 170 ST over TRIB OF TARKIO RVR
S 33 T 66 N R 39 W, Atchison, Missouri
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: 170 ST
The 170 ST bridge in Atchison, Missouri carries 170 ST over TRIB OF TARKIO RVR. It was built in 1950, making it 76 years old today. It was last reconstructed in 1986, extending its service life. The structure is built primarily of steel and spans 1 section, stretching 7.3 meters (24 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 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range. Its NBI inventory load rating is 9.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How 170 ST compares
Live comparison across Missouri.
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 How the historical reference is calculated.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
- 1950
- Last Reconstructed
- 1986
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 7.3 m (24 ft)
- Deck Width
- 6.3 m (21 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 20 vehicles/day
- Structure Number
- 20671
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
How to read this record
This page shows what the last federal inspection recorded, not whether 170 ST 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 170 ST against other structures in Atchison 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 170 ST?
170 ST in Atchison, Missouri 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 170 ST inspected?
170 ST'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. 170 ST 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 170 ST?
170 ST has an NBI inventory load rating of 9.0 metric tons.
Who is responsible for maintaining 170 ST?
170 ST is owned and maintained by County Highway Agency.
How old is 170 ST and does age affect safety?
170 ST was built in 1950, making it 76 years old and last reconstructed in 1986.
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.