US Bridges

Lake Harney Road over Underhill Slough

Poor

Volusia County, Florida · 4 MI South of Maytown Rd. · Structure no. 794050

Built
1948
77 years old
Condition
Poor
inspected October 2023
Type
Culvert
Concrete
Length
39 ft
4 main spans
Daily traffic
130
2023 count
Owner
County
County Highway Agency

About this bridge

Lake Harney Road over Underhill Slough is a concrete culvert carrying Lake Harney Road over Underhill Slough in Volusia County, Florida. It was built in 1948, so it is 77 years old, older than the Florida average of 41.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 130 vehicles a day, roughly 4% of them trucks, projected to reach 226 by 2043. The structure is 39 ft (11.9 m) long. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesLake Harney Road
CrossesUnderhill Slough
Location4 MI South of Maytown Rd.
RouteCounty Highway 0
CountyVolusia County
StateFlorida
Coordinates28.7849, -81.0252
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating79.3 US tons
Inventory rating63.4 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans4
Design loadHS 20
Structure length39 ft (11.9 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 traffic130 (2023)
Projected traffic226 by 2043
Trucks4%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Lake Harney Road over Underhill Slough built?

It was built in 1948, making it 77 years old in 2025.

What condition is Lake Harney Road over Underhill Slough in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in October 2023.

How much traffic does Lake Harney Road over Underhill Slough carry?

About 130 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Lake Harney Road over Underhill Slough?

The structure is 39 ft (11.9 m) long with a longest span of 10 ft (3 m).

Who owns Lake Harney Road over Underhill Slough?

It is owned by the County Highway Agency.