US Bridges

Iris ST over Richland CR

Good

Macon County, Missouri · S 21 T 60 N R 15 W · Structure no. 13880

Built
1994
31 years old
Condition
Good
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 Richland CR is a steel stringer/multi-beam or girder carrying Iris ST over Richland CR in Macon County, Missouri. It was built in 1994, so it is 31 years old, younger than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

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 18 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesIris ST
CrossesRichland CR
LocationS 21 T 60 N R 15 W
RouteCounty Highway 50
CountyMacon County
StateMissouri
Coordinates39.99429, -92.57241
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.5 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length40 ft (12.2 m)
Longest span39 ft (11.9 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.3 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 closed3.7 mi (6 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 Richland CR built?

It was built in 1994, making it 31 years old in 2025.

What condition is Iris ST over Richland CR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2023.

How much traffic does Iris ST over Richland CR carry?

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

How long is Iris ST over Richland CR?

The structure is 40 ft (12.2 m) long with a longest span of 39 ft (11.9 m) and a deck 18 ft wide.

Who owns Iris ST over Richland CR?

It is owned by the County Highway Agency.