Structure 58C0103 · Imperial County, CA

Keystone RD over Alamo River

Carries Keystone RD over Alamo River, 1.5 Mi E/o Mcconnell RD.

Overall conditionFair

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

How ratings work
Decksets the rating5/9 · Fair
Superstructuresets the rating5/9 · Fair
Substructure7/9 · Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT108 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9 · sets the ratingSuperstructure 5/9 · sets the ratingSubstructure 7/9

108 ft end to end, longest span 35 ft. 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.

Built197947 years old
Length107.9 ft32.9 m
Daily traffic922counted 2020
Last inspectedJanuary 2024every 24 months

Location

StateCalifornia
CountyImperial
Location1.5 Mi E/o Mcconnell RD
CarriesKeystone RD
CrossesAlamo River
Coordinates32.91642, -115.45735

Physical Characteristics

MaterialConcrete Continuous
DesignSlab
Total Length107.9 ft (32.9 m)
Max Span35.1 ft (10.7 m)
Deck Width32.5 ft (9.9 m)
Deck Area325.7 sq m
Main Spans3
Year Built1979

Traffic

Avg Daily Traffic922 (2020)
Truck Traffic1%
Lanes On Bridge2

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure Number58C0103

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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