SOUTH MAIN ST
Carrying SOUTH MAIN ST over LAS TRAMPAS CREEK
0.1 MI S OLYMPIC BLVD, Contra Costa, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
SOUTH MAIN ST in Contra Costa, California sits above 3% of rated California bridges on inventory load rating (16 t), while its 1919 build year is earlier than 100% of Contra Costa's recorded-year cohort (618 bridges).
SOUTH MAIN ST in Contra Costa, California is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1919, 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:28C0075
PRE-1950 · CONCRETE · LONG-SPAN-RUN · TIED-CTRL · HEAVY-ADT · LIGHT-LOAD · CAT-GOOD
- PRE-1950 Pre-1950
- CONCRETE Concrete
- LONG-SPAN-RUN 5 spans
- TIED-CTRL Tied control
- HEAVY-ADT Heavy ADT
- LIGHT-LOAD Light 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: SOUTH MAIN ST
The SOUTH MAIN ST bridge in Contra Costa, California carries SOUTH MAIN ST over LAS TRAMPAS CREEK. It was built in 1919, making it 107 years old today. It was last reconstructed in 1956, extending its service life. The structure is built primarily of concrete continuous and spans 5 sections, stretching 39.9 meters (131 feet) end to end. Daily traffic averages 17,700 vehicles, placing it in the heavily-trafficked tier of California bridges. It is owned and maintained by City/Municipal 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. All reported major components score above the Poor range.
How SOUTH MAIN ST compares
Age against the county: built in 1919, earlier than 616 of Contra Costa's 618 bridges with a recorded construction year (100%), against a county median build year of 1971. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
SOUTH MAIN ST vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
16 Top 97% higher than 3% 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.
Contra Costa inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 618 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
- 1919
- Last Reconstructed
- 1956
- Material
- Concrete Continuous
- Number of Spans
- 5
- Structure Length
- 39.9 m (131 ft)
- Deck Width
- 20.0 m (66 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 17,700 vehicles/day
- Structure Number
- 28C0075
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
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 SOUTH MAIN ST 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 SOUTH MAIN ST against other structures in Contra Costa 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 SOUTH MAIN ST?
SOUTH MAIN ST in Contra Costa, 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 SOUTH MAIN ST inspected?
SOUTH MAIN 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 17,700 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SOUTH MAIN ST 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 SOUTH MAIN ST?
SOUTH MAIN ST has an NBI inventory load rating of 15.6 metric tons.
Who is responsible for maintaining SOUTH MAIN ST?
SOUTH MAIN ST is owned and maintained by City/Municipal Highway Agency.
How old is SOUTH MAIN ST and does age affect safety?
SOUTH MAIN ST was built in 1919, making it 107 years old and last reconstructed in 1956.
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.