US Bridges

Kahlon Road over Duck Slough

Fair

Merced County, California · 2.3 MI SE of E Mission RD · Structure no. 39C0374

Built
1914
111 years old, rebuilt 2015
Condition
Fair
inspected September 2024
Type
Tee Beam
Concrete Continuous
Length
76 ft
5 main spans
Daily traffic
384
2018 count
Owner
County
County Highway Agency

About this bridge

Kahlon Road over Duck Slough is a concrete continuous tee beam carrying Kahlon Road over Duck Slough in Merced County, California. It was built in 1914 and reconstructed in 2015, so it is 111 years old, older than the California average of 54.8 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 384 vehicles a day, projected to reach 1,121 by 2042. The structure is 76 ft (23.2 m) long and 49 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesKahlon Road
CrossesDuck Slough
Location2.3 MI SE of E Mission RD
RouteCounty Highway 0
CountyMerced County
StateCalifornia
Coordinates37.25017, -120.41057
Functional classRural Minor 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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 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 geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.4 US tons
Inventory rating24.3 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length76 ft (23.2 m)
Longest span21 ft (6.4 m)
Deck width49 ft (15 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic384 (2018)
Projected traffic1,121 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 Kahlon Road over Duck Slough built?

It was built in 1914, making it 111 years old in 2025. It was reconstructed in 2015.

What condition is Kahlon Road over Duck Slough 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 2024.

How much traffic does Kahlon Road over Duck Slough carry?

About 384 vehicles per day (2018 count).

How long is Kahlon Road over Duck Slough?

The structure is 76 ft (23.2 m) long with a longest span of 21 ft (6.4 m) and a deck 49 ft wide.

Who owns Kahlon Road over Duck Slough?

It is owned by the County Highway Agency.