US Bridges

County RD 306 over Johnson CR

FairPosted for load

Livingston County, Missouri · S 1 T 56 N R 23 W · Structure no. 23684

Built
1940
85 years old
Condition
Fair
inspected January 2025
Type
Girder and Floorbeam System
Steel
Length
38 ft
1 main span
Daily traffic
20
2024 count
Owner
County
County Highway Agency

About this bridge

County RD 306 over Johnson CR is a steel girder and floorbeam system carrying County RD 306 over Johnson CR in Livingston County, Missouri. It was built in 1940, so it is 85 years old, older than the Missouri average of 45.1 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. Its operating status is: posted for load restriction.

It carries about 20 vehicles a day, roughly 10% of them trucks, projected to reach 22 by 2044. The structure is 38 ft (11.6 m) long and 18 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesCounty RD 306
CrossesJohnson CR
LocationS 1 T 56 N R 23 W
RouteCounty Highway 424
CountyLivingston County
StateMissouri
Coordinates39.69792, -93.43674
Functional classRural Local

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.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating18.8 US tons
Inventory rating9.9 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length38 ft (11.6 m)
Longest span37 ft (11.3 m)
Deck width18 ft (5.5 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2024)
Projected traffic22 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$327,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 306 over Johnson CR built?

It was built in 1940, making it 85 years old in 2025.

What condition is County RD 306 over Johnson CR 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 January 2025.

How much traffic does County RD 306 over Johnson CR carry?

About 20 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County RD 306 over Johnson CR?

The structure is 38 ft (11.6 m) long with a longest span of 37 ft (11.3 m) and a deck 18 ft wide.

Who owns County RD 306 over Johnson CR?

It is owned by the County Highway Agency.