Structure 28C0075 · Contra Costa County, CA

South Main ST over Las Trampas Creek

Carries South Main ST over Las Trampas Creek, 0.1 Mi S Olympic BLVD.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.

How ratings work
Decksets the rating7/9 · Good
Superstructuresets the rating7/9 · Good
Substructuresets the rating7/9 · Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT131 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

131 ft end to end, longest span 28 ft. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a tee-beam bridge.

Built1919rebuilt 1956
Length130.9 ft39.9 m
Daily traffic17,700counted 2019
Last inspectedJanuary 2025every 24 months

Location

StateCalifornia
CountyContra Costa
Location0.1 Mi S Olympic BLVD
CarriesSouth Main ST
CrossesLas Trampas Creek
Coordinates37.89471, -122.05891

Physical Characteristics

MaterialConcrete Continuous
DesignTee Beam
Total Length130.9 ft (39.9 m)
Max Span27.9 ft (8.5 m)
Deck Width65.6 ft (20 m)
Deck Area798 sq m
Main Spans5
Year Built1919 (reconstructed 1956)

Traffic

Avg Daily Traffic17,700 (2019)
Truck Traffic3%
Lanes On Bridge5

Inspection & Ownership

Last InspectionJanuary 2025
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number28C0075

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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