US Bridges

Heron ST over Unnamed Br

Fair

Macon County, Missouri · S 9 T 56 N R 15 W · Structure no. 24175

Built
1989
36 years old, rebuilt 1998
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
15
2024 count
Owner
County
County Highway Agency

About this bridge

Heron ST over Unnamed Br is a steel stringer/multi-beam or girder carrying Heron ST over Unnamed Br in Macon County, Missouri. It was built in 1989 and reconstructed in 1998, so it is 36 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 15 vehicles a day, roughly 10% of them trucks, projected to reach 17 by 2044. The structure is 35 ft (10.7 m) long and 16 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesHeron ST
CrossesUnnamed Br
LocationS 9 T 56 N R 15 W
RouteCounty Highway 461
CountyMacon County
StateMissouri
Coordinates39.66669, -92.59111
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 inspectionJanuary 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 geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating98.2 US tons
Inventory rating82.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length35 ft (10.7 m)
Longest span34 ft (10.4 m)
Deck width16 ft (4.8 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15 (2024)
Projected traffic17 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Heron ST over Unnamed Br built?

It was built in 1989, making it 36 years old in 2025. It was reconstructed in 1998.

What condition is Heron ST over Unnamed Br 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 2024.

How much traffic does Heron ST over Unnamed Br carry?

About 15 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Heron ST over Unnamed Br?

The structure is 35 ft (10.7 m) long with a longest span of 34 ft (10.4 m) and a deck 16 ft wide.

Who owns Heron ST over Unnamed Br?

It is owned by the County Highway Agency.