Structure 49 0179 · San Luis Obispo County, CA

State Route 166 over Alamo Creek

Carries State Route 166 over Alamo Creek, 05-slo-166-17.73.

Overall conditionGood

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

How ratings work
Decksets the rating7/9 · Good
Superstructure8/9 · Very Good
Substructuresets the rating7/9 · Good
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT466 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9 · sets the ratingSuperstructure 8/9Substructure 7/9 · sets the rating

466 ft end to end, longest span 115 ft: about 6 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 multi-beam bridge.

Built195967 years old
Length465.6 ft141.9 m
Daily traffic2,600counted 2009
Last inspectedMay 2024every 24 months

Location

StateCalifornia
CountySan Luis Obispo
Location05-slo-166-17.73
CarriesState Route 166
CrossesAlamo Creek
Coordinates35.02366, -120.30469

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length465.6 ft (141.9 m)
Max Span115.2 ft (35.1 m)
Deck Width33.5 ft (10.2 m)
Deck Area1447.4 sq m
Main Spans4
Year Built1959

Traffic

Avg Daily Traffic2,600 (2009)
Truck Traffic24%
Lanes On Bridge2

Inspection & Ownership

Last InspectionMay 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure Number49 0179

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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