US Bridges

US-1 SB (SR-15) over Car Seat Creek

Fair

Nassau County, Florida · 1.9 Mi. N. of SR-200 · Structure no. 740014

Built
1924
101 years old, rebuilt 1989
Condition
Fair
inspected June 2024
Type
Slab
Concrete
Length
42 ft
2 main spans
Daily traffic
8,100
2023 count
Owner
State
State Highway Agency

About this bridge

US-1 SB (SR-15) over Car Seat Creek is a concrete slab carrying US-1 SB (SR-15) over Car Seat Creek in Nassau County, Florida. It was built in 1924 and reconstructed in 1989, so it is 101 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 8,100 vehicles a day, roughly 13% of them trucks, projected to reach 14,054 by 2045. The structure is 42 ft (12.8 m) long and 57 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS-1 SB (SR-15)
CrossesCar Seat Creek
Location1.9 Mi. N. of SR-200
RouteU.S. Route 1
CountyNassau County
StateFlorida
Coordinates30.58841, -81.8302
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating28.7 US tons
Inventory rating22.2 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadOther
Structure length42 ft (12.8 m)
Longest span20 ft (6.1 m)
Deck width57 ft (17.4 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,100 (2023)
Projected traffic14,054 by 2045
Trucks13%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US-1 SB (SR-15) over Car Seat Creek built?

It was built in 1924, making it 101 years old in 2025. It was reconstructed in 1989.

What condition is US-1 SB (SR-15) over Car Seat Creek 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 2024.

How much traffic does US-1 SB (SR-15) over Car Seat Creek carry?

About 8,100 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is US-1 SB (SR-15) over Car Seat Creek?

The structure is 42 ft (12.8 m) long with a longest span of 20 ft (6.1 m) and a deck 57 ft wide.

Who owns US-1 SB (SR-15) over Car Seat Creek?

It is owned by the State Highway Agency.