US Bridges

US-17 (SR-5) over St. Marys River

Fair

Nassau County, Florida · Fl. - Ga. State Line · Structure no. 740008

Built
1927
98 years old, rebuilt 2005
Condition
Fair
inspected April 2024
Type
Movable - Swing
Steel
Length
563 ft
2 main spans
Daily traffic
4,600
2023 count
Owner
State
State Highway Agency

About this bridge

US-17 (SR-5) over St. Marys River is a steel movable - swing carrying US-17 (SR-5) over St. Marys River in Nassau County, Florida. It was built in 1927 and reconstructed in 2005, so it is 98 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 4,600 vehicles a day, roughly 4% of them trucks, projected to reach 7,981 by 2044. The structure is 563 ft (171.5 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesUS-17 (SR-5)
CrossesSt. Marys River
LocationFl. - Ga. State Line
RouteU.S. Route 17
CountyNassau County
StateFlorida
Coordinates30.74166, -81.68797
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating59.6 US tons
Inventory rating35.8 US tons

Structure

Structure typeMovable - Swing
MaterialSteel
DeckOpen grating
Main spans2 (+8 approach)
Design loadH 15
Structure length563 ft (171.5 m)
Longest span101 ft (30.8 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6 m)
Vertical clearance over deck16 ft (5 m)

Traffic and service

Average daily traffic4,600 (2023)
Projected traffic7,981 by 2044
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.8 million
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US-17 (SR-5) over St. Marys River built?

It was built in 1927, making it 98 years old in 2025. It was reconstructed in 2005.

What condition is US-17 (SR-5) over St. Marys River 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 April 2024.

How much traffic does US-17 (SR-5) over St. Marys River carry?

About 4,600 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is US-17 (SR-5) over St. Marys River?

The structure is 563 ft (171.5 m) long with a longest span of 101 ft (30.8 m) and a deck 22 ft wide.

Who owns US-17 (SR-5) over St. Marys River?

It is owned by the State Highway Agency.