US Bridges

Platt Street over Hillsborough River

Fair

Hillsborough County, Florida · At Bayshore Blvd · Structure no. 105500

Built
1926
99 years old
Condition
Fair
inspected September 2023
Type
Movable - Bascule
Steel
Length
421 ft
1 main span
Daily traffic
20,500
2023 count
Owner
County
County Highway Agency

About this bridge

Platt Street over Hillsborough River is a steel movable - bascule carrying Platt Street over Hillsborough River in Hillsborough County, Florida. It was built in 1926, so it is 99 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 20,500 vehicles a day, roughly 9% of them trucks, projected to reach 25,625 by 2042. The structure is 421 ft (128.3 m) long and 59 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesPlatt Street
CrossesHillsborough River
LocationAt Bayshore Blvd
RouteCity Street 0
CountyHillsborough County
StateFlorida
Coordinates27.94174, -82.45848
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 alignment6: Equal to present minimum criteria
Operating rating42.1 US tons
Inventory rating25.2 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+8 approach)
Design loadHS 20
Structure length421 ft (128.3 m)
Longest span111 ft (33.8 m)
Deck width59 ft (18.1 m)
Roadway width40 ft (12.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20,500 (2023)
Projected traffic25,625 by 2042
Trucks9%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Platt Street over Hillsborough River built?

It was built in 1926, making it 99 years old in 2025.

What condition is Platt Street over Hillsborough 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 September 2023.

How much traffic does Platt Street over Hillsborough River carry?

About 20,500 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is Platt Street over Hillsborough River?

The structure is 421 ft (128.3 m) long with a longest span of 111 ft (33.8 m) and a deck 59 ft wide.

Who owns Platt Street over Hillsborough River?

It is owned by the County Highway Agency.