Structure 34 0104 · San Francisco County, CA

US Highway 101 NB over Bayshore BLVD Viaduct

Carries US Highway 101 NB over Bayshore BLVD Viaduct, 04-sf-101-1.14-sf.

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
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT645 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

645 ft end to end, longest span 30 ft: about 1.8 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 slab bridge.

Built197056 years old
Length645.0 ft196.6 m
Daily traffic195,400counted 2019
Last inspectedJanuary 2024every 48 months

Location

StateCalifornia
CountySan Francisco
Location04-sf-101-1.14-sf
CarriesUS Highway 101 NB
CrossesBayshore BLVD Viaduct
Coordinates37.72398, -122.40109

Physical Characteristics

MaterialConcrete Continuous
DesignSlab
Total Length645.0 ft (196.6 m)
Max Span29.9 ft (9.1 m)
Deck Width22.0 ft (6.7 m)
Deck Area1317.2 sq m
Main Spans22
Year Built1970

Traffic

Avg Daily Traffic195,400 (2019)
Truck Traffic5%
Lanes On Bridge10

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 48 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number34 0104

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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