Structure 53 1240 · Los Angeles County, CA

Interstate 405 over 120th Street

Carries Interstate 405 over 120th Street, 07-la-405-r20.73-eseg.

Overall conditionGood

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

How ratings work
Decksets the rating7/9 · Good
Superstructuresets the rating7/9 · Good
Substructure8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT147 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9 · sets the ratingSuperstructure 7/9 · sets the ratingSubstructure 8/9

147 ft end to end, longest span 85 ft: about 2 semi-trucks nose to tail. 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 box-beam bridge.

Built1963rebuilt 1989
Length147.0 ft44.8 m
Daily traffic261,000counted 2022
Last inspectedNovember 2024every 24 months

Location

StateCalifornia
CountyLos Angeles
Location07-la-405-r20.73-eseg
CarriesInterstate 405
Crosses120th Street
Coordinates33.92369, -118.36836

Physical Characteristics

MaterialConcrete Continuous
DesignBox Beam - Multiple
Total Length147.0 ft (44.8 m)
Max Span85.0 ft (25.9 m)
Deck Width171.6 ft (52.3 m)
Deck Area2343.0 sq m
Main Spans3
Year Built1963 (reconstructed 1989)

Traffic

Avg Daily Traffic261,000 (2022)
Truck Traffic5%
Lanes On Bridge12
Lanes Under Bridge4

Inspection & Ownership

Last InspectionNovember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number53 1240

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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