IS 55 N
Carrying IS 55 N over CST BROADWAY ST
S 4 T 44 N R 7 E, St. Louis city, Missouri
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: IS 55 N
The IS 55 N bridge in St. Louis city, Missouri carries IS 55 N over CST BROADWAY ST. It was built in 1963, making it 63 years old today. The structure is built primarily of concrete continuous. Daily traffic averages 12,321 vehicles, placing it in the heavily-trafficked tier of Missouri bridges.
The latest FHWA inspection records show limited component ratings on file. The weakest component sits in unrated condition. All reported major components score above the Poor range.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How IS 55 N 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 How the historical reference is calculated.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
- 1963
- Material
- Concrete Continuous
- Avg Daily Traffic
- 12,321 vehicles/day
- Structure Number
- 877
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 IS 55 N 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 IS 55 N against other structures in St. Louis city 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 IS 55 N?
IS 55 N in St. Louis city, Missouri on the FHWA's 0–9 scale.
How often is IS 55 N inspected?
IS 55 N'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 12,321 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IS 55 N is currently shown as unrated condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for IS 55 N?
An inventory load rating is not recorded for IS 55 N.
Who is responsible for maintaining IS 55 N?
Ownership is not specified for IS 55 N in the NBI.
How old is IS 55 N and does age affect safety?
IS 55 N was built in 1963, making it 63 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.
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.