Structure 900003 · Monroe County, FL

US 1 SB (900074) over Boca Chica Channel

Carries US 1 SB (900074) over Boca Chica Channel, Boca Chica Key (mm 6.0).

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

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT2,635 FT OVERALL500 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

2,635 ft end to end, longest span 62 ft: about 7.3 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.

Built197353 years old
Length2634.8 ft803.1 m
Daily traffic13,500counted 2025
Last inspectedJanuary 2025every 24 months

Location

StateFlorida
CountyMonroe
LocationBoca Chica Key (mm 6.0)
CarriesUS 1 SB (900074)
CrossesBoca Chica Channel
Coordinates24.57760, -81.71634

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length2634.8 ft (803.1 m)
Max Span62.0 ft (18.9 m)
Deck Width42.3 ft (12.9 m)
Deck Area10360.0 sq m
Main Spans43
Year Built1973

Traffic

Avg Daily Traffic13,500 (2025)
Truck Traffic10%
Lanes On Bridge2

Inspection & Ownership

Last InspectionJanuary 2025
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number900003

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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