US Bridges

I-75 SB to I-4 over Sligh Avenue

Fair

Hillsborough County, Florida · I-4 & I-75 Interchange · Structure no. 100430

Built
1985
40 years old, rebuilt 2019
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
233 ft
3 main spans
Daily traffic
14,500
2023 count
Owner
State
State Highway Agency

About this bridge

I-75 SB to I-4 over Sligh Avenue is a prestressed concrete stringer/multi-beam or girder carrying I-75 SB to I-4 over Sligh Avenue in Hillsborough County, Florida. It was built in 1985 and reconstructed in 2019, so it is 40 years old, younger 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 14,500 vehicles a day, roughly 9% of them trucks, projected to reach 25,158 by 2042. The structure is 233 ft (71 m) long and 47 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesI-75 SB to I-4
CrossesSligh Avenue
LocationI-4 & I-75 Interchange
RouteInterstate 75
CountyHillsborough County
StateFlorida
Coordinates28.00539, -82.32936
Functional classUrban Principal Arterial - Interstate

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.
Substructure8 Very GoodNo problems noted.
Last inspectionDecember 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 rating48 US tons
Inventory rating37.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length233 ft (71 m)
Longest span117 ft (35.7 m)
Deck width47 ft (14.3 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,500 (2023)
Projected traffic25,158 by 2042
Trucks9%
Lanes on structure1
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkSTRAHNET connector

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 I-75 SB to I-4 over Sligh Avenue built?

It was built in 1985, making it 40 years old in 2025. It was reconstructed in 2019.

What condition is I-75 SB to I-4 over Sligh Avenue 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 December 2023.

How much traffic does I-75 SB to I-4 over Sligh Avenue carry?

About 14,500 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is I-75 SB to I-4 over Sligh Avenue?

The structure is 233 ft (71 m) long with a longest span of 117 ft (35.7 m) and a deck 47 ft wide.

Who owns I-75 SB to I-4 over Sligh Avenue?

It is owned by the State Highway Agency.