Structure 4 0286 · Humboldt County, CA

U.s. Highway 101 over Boyes Creek

Carries U.s. Highway 101 over Boyes Creek, 01-hum-101-r128.97.

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
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT1,273 FT OVERALL250 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

1,273 ft end to end, longest span 190 ft: about 3.5 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 box-beam bridge.

Built198937 years old
Length1273.0 ft388 m
Daily traffic3,100counted 2009
Last inspectedJuly 2024every 24 months

Location

StateCalifornia
CountyHumboldt
Location01-hum-101-r128.97
CarriesU.s. Highway 101
CrossesBoyes Creek
Coordinates41.36928, -123.99110

Physical Characteristics

MaterialPrestressed Concrete Continuous
DesignBox Beam - Multiple
Total Length1273.0 ft (388 m)
Max Span190.0 ft (57.9 m)
Deck Width73.8 ft (22.5 m)
Deck Area8,730 sq m
Main Spans7
Year Built1989

Traffic

Avg Daily Traffic3,100 (2009)
Truck Traffic15%
Lanes On Bridge4

Inspection & Ownership

Last InspectionJuly 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number04 0286

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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