OLD HWY 91
Carrying OLD HWY 91 over UPRR;N.SPENCER RR OP
13.1 N. 5.2 W. SPENCER, Clark, Idaho
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: OLD HWY 91
The OLD HWY 91 bridge in Clark, Idaho carries OLD HWY 91 over UPRR;N.SPENCER RR OP. It was built in 1936, making it 90 years old today. The structure is built primarily of steel and spans 1 section, stretching 90.2 meters (296 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of Idaho bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order. 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 OLD HWY 91 compares
Live comparison across Idaho.
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 How the historical reference is calculated.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
- 1936
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 90.2 m (296 ft)
- Deck Width
- 7.7 m (25 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 000000000031565
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
- • The superstructure (beams and supports above the deck) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
OLD HWY 91 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare OLD HWY 91 against other structures in Clark and across Idaho. Idaho 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 OLD HWY 91?
OLD HWY 91 in Clark, Idaho has a deck rating of 4/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is OLD HWY 91 inspected?
OLD HWY 91'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 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. OLD HWY 91 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for OLD HWY 91?
OLD HWY 91 has an NBI inventory load rating of 24.5 metric tons.
Who is responsible for maintaining OLD HWY 91?
OLD HWY 91 is owned and maintained by County Highway Agency.
How old is OLD HWY 91 and does age affect safety?
OLD HWY 91 was built in 1936, making it 90 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.