Structure 28 0147 · Contra Costa County, CA

State Route 242 over Holbrook Channel

Carries State Route 242 over Holbrook Channel, 04-cc-242-r2.65-cnd.

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
CAR · 15 FT51 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

51 ft end to end. Lengths and the car 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 slab bridge.

Built1978rebuilt 2000
Length50.9 ft15.5 m
Daily traffic100,000counted 2009
Last inspectedJanuary 2024every 48 months

Location

StateCalifornia
CountyContra Costa
Location04-cc-242-r2.65-cnd
CarriesState Route 242
CrossesHolbrook Channel
Coordinates37.99537, -122.03874

Physical Characteristics

MaterialPrestressed Concrete
DesignSlab
Total Length50.9 ft (15.5 m)
Max Span49.9 ft (15.2 m)
Deck Width190.6 ft (58.1 m)
Deck Area900.5 sq m
Main Spans1
Year Built1978 (reconstructed 2000)

Traffic

Avg Daily Traffic100,000 (2009)
Truck Traffic5%
Lanes On Bridge6

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 48 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number28 0147

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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