Structure 20 0134 · Sonoma County, CA

US Highway 101 over Ninth Street

Carries US Highway 101 over Ninth Street, 04-son-101-20.48-sro.

Overall conditionFair

Set by its lowest-rated component: Deck at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructure7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT151 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

151 ft end to end, longest span 91 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.

Built1968rebuilt 2009
Length150.9 ft46 m
Daily traffic96,000counted 2016
Last inspectedAugust 2024every 24 months

Location

StateCalifornia
CountySonoma
Location04-son-101-20.48-sro
CarriesUS Highway 101
CrossesNinth Street
Coordinates38.44227, -122.72124

Physical Characteristics

MaterialConcrete Continuous
DesignBox Beam - Multiple
Total Length150.9 ft (46 m)
Max Span90.9 ft (27.7 m)
Deck Width136.2 ft (41.5 m)
Deck Area1,909 sq m
Main Spans3
Year Built1968 (reconstructed 2009)

Traffic

Avg Daily Traffic96,000 (2016)
Truck Traffic6%
Lanes On Bridge8
Lanes Under Bridge2

Inspection & Ownership

Last InspectionAugust 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number20 0134

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