US Bridges

SR-105 & SR-A1A over Nassau Sound

Good

Nassau County, Florida · 10 Mi. S. of Fernandina · Structure no. 740105

Built
1999
26 years old
Condition
Good
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
5,130 ft
54 main spans
Daily traffic
5,000
2022 count
Owner
State
State Highway Agency

About this bridge

SR-105 & SR-A1A over Nassau Sound is a prestressed concrete stringer/multi-beam or girder carrying SR-105 & SR-A1A over Nassau Sound in Nassau County, Florida. It was built in 1999, so it is 26 years old, younger than the Florida average of 41.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 5,000 vehicles a day, roughly 5% of them trucks, projected to reach 8,675 by 2044. The structure is 5,130 ft (1,563.6 m) long and 47 ft wide.

Location

Open in Google Maps
CarriesSR-105 & SR-A1A
CrossesNassau Sound
Location10 Mi. S. of Fernandina
RouteState Highway 105
CountyNassau County
StateFlorida
Coordinates30.51806, -81.45028
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating61.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans54
Design loadHS 20 + Mod
Structure length5,130 ft (1,563.6 m)
Longest span95 ft (28.9 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,000 (2022)
Projected traffic8,675 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

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 SR-105 & SR-A1A over Nassau Sound built?

It was built in 1999, making it 26 years old in 2025.

What condition is SR-105 & SR-A1A over Nassau Sound in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2023.

How much traffic does SR-105 & SR-A1A over Nassau Sound carry?

About 5,000 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is SR-105 & SR-A1A over Nassau Sound?

The structure is 5,130 ft (1,563.6 m) long with a longest span of 95 ft (28.9 m) and a deck 47 ft wide.

Who owns SR-105 & SR-A1A over Nassau Sound?

It is owned by the State Highway Agency.