US Bridges

CR 121 over Dunn Creek

Fair

Nassau County, Florida · 1.8 MI North of CR 115 · Structure no. 740052

Built
1949
76 years old
Condition
Fair
inspected June 2024
Type
Culvert
Concrete
Length
29 ft
3 main spans
Daily traffic
2,500
2024 count
Owner
County
County Highway Agency

About this bridge

CR 121 over Dunn Creek is a concrete culvert carrying CR 121 over Dunn Creek in Nassau County, Florida. It was built in 1949, so it is 76 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 2,500 vehicles a day, roughly 5% of them trucks, projected to reach 4,338 by 2046. The structure is 29 ft (8.8 m) long. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesCR 121
CrossesDunn Creek
Location1.8 MI North of CR 115
RouteCounty Highway 121
CountyNassau County
StateFlorida
Coordinates30.70756, -82.02161
Functional classRural Major 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
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating33.1 US tons
Inventory rating21.2 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadUnknown
Structure length29 ft (8.8 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,500 (2024)
Projected traffic4,338 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was CR 121 over Dunn Creek built?

It was built in 1949, making it 76 years old in 2025.

What condition is CR 121 over Dunn 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 CR 121 over Dunn Creek carry?

About 2,500 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is CR 121 over Dunn Creek?

The structure is 29 ft (8.8 m) long with a longest span of 10 ft (3 m).

Who owns CR 121 over Dunn Creek?

It is owned by the County Highway Agency.