US Bridges

Duck Key Drive over Toms Harbor Channel

Fair

Monroe County, Florida · 50FT. E of US-1 MM61 · Structure no. 904600

Built
1967
58 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
248 ft
5 main spans
Daily traffic
1,700
2023 count
Owner
County
County Highway Agency

About this bridge

Duck Key Drive over Toms Harbor Channel is a prestressed concrete stringer/multi-beam or girder carrying Duck Key Drive over Toms Harbor Channel in Monroe County, Florida. It was built in 1967, so it is 58 years old, older than the Florida average of 41.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 1,700 vehicles a day, roughly 9% of them trucks, projected to reach 3,032 by 2042. The structure is 248 ft (75.6 m) long and 34 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesDuck Key Drive
CrossesToms Harbor Channel
Location50FT. E of US-1 MM61
RouteCounty Highway 0
CountyMonroe County
StateFlorida
Coordinates24.77942, -80.91514
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating48.2 US tons
Inventory rating36.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHL 93
Structure length248 ft (75.6 m)
Longest span50 ft (15.1 m)
Deck width34 ft (10.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,700 (2023)
Projected traffic3,032 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$2.1 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Duck Key Drive over Toms Harbor Channel built?

It was built in 1967, making it 58 years old in 2025.

What condition is Duck Key Drive over Toms Harbor Channel in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in August 2023.

How much traffic does Duck Key Drive over Toms Harbor Channel carry?

About 1,700 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is Duck Key Drive over Toms Harbor Channel?

The structure is 248 ft (75.6 m) long with a longest span of 50 ft (15.1 m) and a deck 34 ft wide.

Who owns Duck Key Drive over Toms Harbor Channel?

It is owned by the County Highway Agency.