MARIPOSA ST
Carrying MARIPOSA ST over CALTRAIN & UP RR
AT SR 280, San Francisco, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: MARIPOSA ST
The MARIPOSA ST bridge in San Francisco, California carries MARIPOSA ST over CALTRAIN & UP RR. It was built in 1968, making it 58 years old today. The structure is built primarily of concrete continuous and spans 2 sections, stretching 30.5 meters (100 feet) end to end. Daily traffic averages 20,000 vehicles, placing it in the heavily-trafficked tier of California bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules. Its NBI inventory load rating is 54.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How MARIPOSA ST 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 How the historical reference is calculated.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
- 1968
- Material
- Concrete Continuous
- Number of Spans
- 2
- Structure Length
- 30.5 m (100 ft)
- Deck Width
- 21.6 m (71 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 20,000 vehicles/day
- Structure Number
- 34C0005
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.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
How to read this record
MARIPOSA ST 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 MARIPOSA ST against other structures in San Francisco 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 MARIPOSA ST?
MARIPOSA ST in San Francisco, California has a deck rating of 4/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is MARIPOSA ST inspected?
MARIPOSA ST'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 20,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. MARIPOSA ST 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 MARIPOSA ST?
MARIPOSA ST has an NBI inventory load rating of 54.4 metric tons.
Who is responsible for maintaining MARIPOSA ST?
MARIPOSA ST is owned and maintained by County Highway Agency.
How old is MARIPOSA ST and does age affect safety?
MARIPOSA ST was built in 1968, making it 58 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.