US Bridges

US-1 (SR-5) over 12 Mile Swamp

Fair

St. Johns County, Florida · 2.8 Mi. S. of CR-210 · Structure no. 780022

Built
1957
68 years old, rebuilt 2002
Condition
Fair
inspected June 2023
Type
Culvert
Concrete
Length
25 ft
2 main spans
Daily traffic
26,000
2022 count
Owner
State
State Highway Agency

About this bridge

US-1 (SR-5) over 12 Mile Swamp is a concrete culvert carrying US-1 (SR-5) over 12 Mile Swamp in St. Johns County, Florida. It was built in 1957 and reconstructed in 2002, so it is 68 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 6 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 26,000 vehicles a day, roughly 3% of them trucks, projected to reach 45,110 by 2044. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS-1 (SR-5)
Crosses12 Mile Swamp
Location2.8 Mi. S. of CR-210
RouteU.S. Route 1
CountySt. Johns County
StateFlorida
Coordinates30.04868, -81.42464
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.8 US tons
Inventory rating30.4 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 20 + Mod
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic26,000 (2022)
Projected traffic45,110 by 2044
Trucks3%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US-1 (SR-5) over 12 Mile Swamp built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 2002.

What condition is US-1 (SR-5) over 12 Mile Swamp 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 June 2023.

How much traffic does US-1 (SR-5) over 12 Mile Swamp carry?

About 26,000 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is US-1 (SR-5) over 12 Mile Swamp?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m).

Who owns US-1 (SR-5) over 12 Mile Swamp?

It is owned by the State Highway Agency.