US Bridges

SR-408 WB over Lake Underhill

Fair

Orange County, Florida · SR-408 WB -Lake Underhill · Structure no. 750121

Built
1973
52 years old, rebuilt 2010
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
1,708 ft
21 main spans
Daily traffic
81,000
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

SR-408 WB over Lake Underhill is a prestressed concrete stringer/multi-beam or girder carrying SR-408 WB over Lake Underhill in Orange County, Florida. It was built in 1973 and reconstructed in 2010, so it is 52 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 81,000 vehicles a day, roughly 5% of them trucks, projected to reach 140,535 by 2044. The structure is 1,708 ft (520.6 m) long and 91 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR-408 WB
CrossesLake Underhill
LocationSR-408 WB -Lake Underhill
RouteState Highway 408
CountyOrange County
StateFlorida
Coordinates28.5385, -81.33692
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating40.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans21
Design loadHS 20 + Mod
Structure length1,708 ft (520.6 m)
Longest span82 ft (25 m)
Deck width91 ft (27.7 m)
Roadway width88 ft (26.8 m)
Vertical clearance over deck20 ft (6 m)

Traffic and service

Average daily traffic81,000 (2023)
Projected traffic140,535 by 2044
Trucks5%
Lanes on structure6
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a toll road
National Highway SystemYes

Ownership and planned work

OwnerState Toll Authority
Maintained byState Toll Authority
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-408 WB over Lake Underhill built?

It was built in 1973, making it 52 years old in 2025. It was reconstructed in 2010.

What condition is SR-408 WB over Lake Underhill 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 April 2024.

How much traffic does SR-408 WB over Lake Underhill carry?

About 81,000 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is SR-408 WB over Lake Underhill?

The structure is 1,708 ft (520.6 m) long with a longest span of 82 ft (25 m) and a deck 91 ft wide.

Who owns SR-408 WB over Lake Underhill?

It is owned by the State Toll Authority.