OLD HIGHWAY 99
Carrying OLD HIGHWAY 99 over HAY CREEK
0.1 MI S TRUITMAN LANE, Siskiyou, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: OLD HIGHWAY 99
The OLD HIGHWAY 99 bridge in Siskiyou, California carries OLD HIGHWAY 99 over HAY CREEK. It was built in 1923, making it 103 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 7.9 meters (26 feet) end to end. Daily traffic averages 1,005 vehicles, placing it in the moderately-trafficked tier of California 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. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 16.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How OLD HIGHWAY 99 compares
Live comparison across California.
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 How the historical reference is calculated.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
- 1923
- Material
- Concrete Continuous
- Number of Spans
- 3
- Structure Length
- 7.9 m (26 ft)
- Deck Width
- 9.7 m (32 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,005 vehicles/day
- Structure Number
- 02C0204
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 OLD HIGHWAY 99 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 OLD HIGHWAY 99 against other structures in Siskiyou and across California. California 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 HIGHWAY 99?
OLD HIGHWAY 99 in Siskiyou, California on the FHWA's 0–9 scale.
How often is OLD HIGHWAY 99 inspected?
OLD HIGHWAY 99'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 1,005 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. OLD HIGHWAY 99 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 OLD HIGHWAY 99?
OLD HIGHWAY 99 has an NBI inventory load rating of 16.2 metric tons.
Who is responsible for maintaining OLD HIGHWAY 99?
OLD HIGHWAY 99 is owned and maintained by County Highway Agency.
How old is OLD HIGHWAY 99 and does age affect safety?
OLD HIGHWAY 99 was built in 1923, making it 103 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.