FHWA NBI 2024 Inspection record Public-domain dataset

N4630 (0124C)

Carrying N4630 (0124C) over CREEK

2E 1.4S OF SH 51, Adair, Oklahoma

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
25 t Inventory load rating

Bridge Snapshot: N4630 (0124C)

The N4630 (0124C) bridge in Adair, Oklahoma carries N4630 (0124C) over CREEK. It was built in 1955, making it 71 years old today. The structure is built primarily of concrete and spans 3 sections, stretching 10.1 meters (33 feet) end to end. Daily traffic averages 253 vehicles, placing it in the lower-traffic tier of Oklahoma bridges. It is owned and maintained by County Highway Agency.

The latest FHWA inspection records show culvert at 5/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 24.5 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How N4630 (0124C) compares

▼ 7.9
Load rating vs Oklahoma average (32.4 t)
Bottom 32%
Lower load rating than 68% of Oklahoma bridges
139
Bridges in Adair · 20 in Poor condition
N4630 (0124C) 24.5 t
Oklahoma average 32.4 t

Live comparison across Oklahoma.

Historical Sufficiency Rating

PlainBridge-computed
81.7 / 100 - historical 80–100 band
Structural adequacy /55
37.8
Serviceability /30
29.0
Essentiality /15
14.9
Special reductions
0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Culvert
5/9
Fair (5–6)
Inventory Load Rating
24.5 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1955
Material
Concrete
Number of Spans
3
Structure Length
10.1 m (33 ft)
Owner
County Highway Agency
Avg Daily Traffic
253 vehicles/day
Structure Number
133410000000000

How to read this record

This page shows what the last federal inspection recorded, not whether N4630 (0124C) 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 N4630 (0124C) against other structures in Adair and across Oklahoma. Oklahoma 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 N4630 (0124C)?

N4630 (0124C) in Adair, Oklahoma on the FHWA's 0–9 scale.

How often is N4630 (0124C) inspected?

N4630 (0124C)'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 253 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. N4630 (0124C) 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 N4630 (0124C)?

N4630 (0124C) has an NBI inventory load rating of 24.5 metric tons.

Who is responsible for maintaining N4630 (0124C)?

N4630 (0124C) is owned and maintained by County Highway Agency.

How old is N4630 (0124C) and does age affect safety?

N4630 (0124C) was built in 1955, making it 71 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.