DE LONG AVENUE
Carrying DE LONG AVENUE over NCRRA (OLD NWP RR)
04-MRN-101-R21.15-NVTO, Marin, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
DE LONG AVENUE in Marin, California sits above 85% of rated California bridges on inventory load rating (40 t), while its 1974 build year is earlier than 18% of Marin's recorded-year cohort (207 bridges).
DE LONG AVENUE in Marin, California is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1974, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure CA:27 0103Y
INTERSTATE-ERA · PRESTRESS · MULTI-SPAN · TIED-CTRL · HEAVY-ADT · STANDARD-LOAD · CAT-GOOD
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- MULTI-SPAN 2 spans
- TIED-CTRL Tied control
- HEAVY-ADT Heavy ADT
- STANDARD-LOAD Standard load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: DE LONG AVENUE
The DE LONG AVENUE bridge in Marin, California carries DE LONG AVENUE over NCRRA (OLD NWP RR). It was built in 1974, making it 52 years old today. The structure is built primarily of prestressed concrete continuous and spans 2 sections, stretching 67.1 meters (220 feet) end to end. Daily traffic averages 30,155 vehicles, placing it in the heavily-trafficked tier of California bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. No reported major component scores in the Poor range under the current federal condition thresholds.
How DE LONG AVENUE compares
Age against the county: built in 1974, earlier than 37 of Marin's 207 bridges with a recorded construction year (18%), against a county median build year of 1959. This is one of the newer structures in its county.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
DE LONG AVENUE vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
40 Top 15% higher than 85% of 25,538 bridges
rated California bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Marin inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 207 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1974
- Material
- Prestressed Concrete Continuous
- Number of Spans
- 2
- Structure Length
- 67.1 m (220 ft)
- Deck Width
- 29.6 m (97 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 30,155 vehicles/day
- Structure Number
- 27 0103Y
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 DE LONG AVENUE 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 DE LONG AVENUE against other structures in Marin 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 DE LONG AVENUE?
DE LONG AVENUE in Marin, California has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is DE LONG AVENUE inspected?
DE LONG AVENUE'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 30,155 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. DE LONG AVENUE is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for DE LONG AVENUE?
DE LONG AVENUE has an NBI inventory load rating of 39.5 metric tons.
Who is responsible for maintaining DE LONG AVENUE?
DE LONG AVENUE is owned and maintained by State Highway Agency.
How old is DE LONG AVENUE and does age affect safety?
DE LONG AVENUE was built in 1974, making it 52 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.