US Bridges

Iris ST over Unnamed Str

Fair

Macon County, Missouri · S 22 T 60 N R 15 W · Structure no. 30646

Built
2003
22 years old
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
40 ft
1 main span
Daily traffic
20
2024 count
Owner
County
County Highway Agency

About this bridge

Iris ST over Unnamed Str is a steel stringer/multi-beam or girder carrying Iris ST over Unnamed Str in Macon County, Missouri. It was built in 2003, so it is 22 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 20 vehicles a day, roughly 10% of them trucks, projected to reach 22 by 2044. The structure is 40 ft (12.2 m) long and 22 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesIris ST
CrossesUnnamed Str
LocationS 22 T 60 N R 15 W
RouteCounty Highway 65
CountyMacon County
StateMissouri
Coordinates39.99353, -92.55688
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 protection7 GoodSome minor problems.
Last inspectionDecember 2023
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating94.2 US tons
Inventory rating56.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length40 ft (12.2 m)
Longest span39 ft (11.9 m)
Deck width22 ft (6.7 m)
Roadway width22 ft (6.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2024)
Projected traffic22 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 Iris ST over Unnamed Str built?

It was built in 2003, making it 22 years old in 2025.

What condition is Iris ST over Unnamed Str 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 December 2023.

How much traffic does Iris ST over Unnamed Str carry?

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

How long is Iris ST over Unnamed Str?

The structure is 40 ft (12.2 m) long with a longest span of 39 ft (11.9 m) and a deck 22 ft wide.

Who owns Iris ST over Unnamed Str?

It is owned by the County Highway Agency.