Structure 34 0033 · San Francisco County, CA

U.s. Highway 101 over 280/101 Ic - Alemany Cir

Carries U.s. Highway 101 over 280/101 Ic - Alemany Cir, 04-sf-101-2.03-sf.

Overall conditionFair

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

How ratings work
Deck7/9 · Good
Superstructuresets the rating5/9 · Fair
Substructure7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT758 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 5/9 · sets the ratingSubstructure 7/9

758 ft end to end, longest span 73 ft: about 2.1 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 multi-beam bridge.

Built1950rebuilt 2020
Length757.9 ft231 m
Daily traffic234,000counted 2018
Last inspectedJanuary 2024every 24 months

Location

StateCalifornia
CountySan Francisco
Location04-sf-101-2.03-sf
CarriesU.s. Highway 101
Crosses280/101 Ic - Alemany Cir
Coordinates37.73605, -122.40712

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length757.9 ft (231 m)
Max Span73.2 ft (22.3 m)
Deck Width87.9 ft (26.8 m)
Deck Area6190.8 sq m
Main Spans13
Year Built1950 (reconstructed 2020)

Traffic

Avg Daily Traffic234,000 (2018)
Truck Traffic3%
Lanes On Bridge6
Lanes Under Bridge9

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number34 0033

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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