Structure 29 0043 · San Joaquin County, CA

State Route 12 over Mokelumne River

Carries State Route 12 over Mokelumne River, 10-sj-012-0.01.

Overall conditionFair

Set by its lowest-rated component: Deck at 5 of 9.

How ratings work
Decksets the rating5/9 · Fair
Superstructure7/9 · Good
Substructure7/9 · Good
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT1,436 FT OVERALL250 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9 · sets the ratingSuperstructure 7/9Substructure 7/9

1,436 ft end to end, longest span 144 ft: about 4.0 football fields. 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 swing bridge (drawn closed).

Built1942rebuilt 1978
Length1436.0 ft437.7 m
Daily traffic15,000counted 2009
Last inspectedApril 2023every 24 months

Location

StateCalifornia
CountySan Joaquin
Location10-sj-012-0.01
CarriesState Route 12
CrossesMokelumne River
Coordinates38.12689, -121.58239

Physical Characteristics

MaterialSteel
DesignMovable - Swing
Total Length1436.0 ft (437.7 m)
Max Span143.7 ft (43.8 m)
Deck Width36.1 ft (11 m)
Deck Area4814.7 sq m
Main Spans2
Year Built1942 (reconstructed 1978)

Traffic

Avg Daily Traffic15,000 (2009)
Truck Traffic14%
Lanes On Bridge2
Lanes Under Bridge2

Inspection & Ownership

Last InspectionApril 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is eligible for the National Register
Scour Critical5 — Stable for scour
Structure Number29 0043

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.

Nearby Bridges