STATE ROUTE 1
Carrying STATE ROUTE 1 over SANTA MARIA RIVER
05-SLO-001-0.01, San Luis Obispo, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: STATE ROUTE 1
The STATE ROUTE 1 bridge in San Luis Obispo, California carries STATE ROUTE 1 over SANTA MARIA RIVER. It was built in 1955, making it 71 years old today. The structure is built primarily of prestressed concrete and spans 24 sections, stretching 366.7 meters (1203 feet) end to end. Daily traffic averages 5,000 vehicles, placing it in the moderately-trafficked tier of California bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 5/9, substructure at 5/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 24.6 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How STATE ROUTE 1 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 How the historical reference is calculated.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
- 1955
- Material
- Prestressed Concrete
- Number of Spans
- 24
- Structure Length
- 366.7 m (1203 ft)
- Deck Width
- 10.1 m (33 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 5,000 vehicles/day
- Structure Number
- 49 0042
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates poor at 4/9, advanced deterioration that should be prioritized for repair.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
How to read this record
STATE ROUTE 1 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 STATE ROUTE 1 against other structures in San Luis Obispo 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 STATE ROUTE 1?
STATE ROUTE 1 in San Luis Obispo, California has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is STATE ROUTE 1 inspected?
STATE ROUTE 1'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 5,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. STATE ROUTE 1 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 STATE ROUTE 1?
STATE ROUTE 1 has an NBI inventory load rating of 24.6 metric tons.
Who is responsible for maintaining STATE ROUTE 1?
STATE ROUTE 1 is owned and maintained by State Highway Agency.
How old is STATE ROUTE 1 and does age affect safety?
STATE ROUTE 1 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.
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.