US Bridges

Decoy ST over Unnamed CR

Fair

Macon County, Missouri · S 30 T 57 N R 16 W · Structure no. 23349

Built
1991
34 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
31 ft
1 main span
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

Decoy ST over Unnamed CR is a steel stringer/multi-beam or girder carrying Decoy ST over Unnamed CR in Macon County, Missouri. It was built in 1991, so it is 34 years old, younger 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.

It carries about 35 vehicles a day, roughly 10% of them trucks, projected to reach 39 by 2044. The structure is 31 ft (9.4 m) long and 16 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesDecoy ST
CrossesUnnamed CR
LocationS 30 T 57 N R 16 W
RouteCounty Highway 405
CountyMacon County
StateMissouri
Coordinates39.71712, -92.74359
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
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 inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating69.4 US tons
Inventory rating46.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length31 ft (9.4 m)
Longest span30 ft (9.1 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic39 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$196,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Decoy ST over Unnamed CR built?

It was built in 1991, making it 34 years old in 2025.

What condition is Decoy ST over Unnamed 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 February 2024.

How much traffic does Decoy ST over Unnamed CR carry?

About 35 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Decoy ST over Unnamed CR?

The structure is 31 ft (9.4 m) long with a longest span of 30 ft (9.1 m) and a deck 16 ft wide.

Who owns Decoy ST over Unnamed CR?

It is owned by the County Highway Agency.