US Bridges

21st Avenue over I-75/SR-93

Fair

Hillsborough County, Florida · 2MI S of SR-674 · Structure no. 100354

Built
1981
44 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
557 ft
4 main spans
Daily traffic
500
2023 count
Owner
State
State Highway Agency

About this bridge

21st Avenue over I-75/SR-93 is a steel continuous stringer/multi-beam or girder carrying 21st Avenue over I-75/SR-93 in Hillsborough County, Florida. It was built in 1981, so it is 44 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 500 vehicles a day, roughly 2% of them trucks, projected to reach 868 by 2042. The structure is 557 ft (169.8 m) long and 47 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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Carries21st Avenue
CrossesI-75/SR-93
Location2MI S of SR-674
RouteCounty Highway 0
CountyHillsborough County
StateFlorida
Coordinates27.69469, -82.40951
Functional classUrban Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78 US tons
Inventory rating47 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length557 ft (169.8 m)
Longest span224 ft (68.4 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic500 (2023)
Projected traffic868 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.9 mi (3 km)
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was 21st Avenue over I-75/SR-93 built?

It was built in 1981, making it 44 years old in 2025.

What condition is 21st Avenue over I-75/SR-93 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 September 2023.

How much traffic does 21st Avenue over I-75/SR-93 carry?

About 500 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is 21st Avenue over I-75/SR-93?

The structure is 557 ft (169.8 m) long with a longest span of 224 ft (68.4 m) and a deck 47 ft wide.

Who owns 21st Avenue over I-75/SR-93?

It is owned by the State Highway Agency.