US Bridges

Iris ST over Long Br

Good

Macon County, Missouri · S 19 T 60 N R 14 W · Structure no. 14638

Built
1994
31 years old
Condition
Good
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
30
2024 count
Owner
County
County Highway Agency

About this bridge

Iris ST over Long Br is a steel stringer/multi-beam or girder carrying Iris ST over Long Br 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 30 vehicles a day, roughly 10% of them trucks, projected to reach 33 by 2044. The structure is 35 ft (10.7 m) long and 18 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesIris ST
CrossesLong Br
LocationS 19 T 60 N R 14 W
RouteCounty Highway 72
CountyMacon County
StateMissouri
Coordinates39.99223, -92.50936
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 evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.6 US tons
Inventory rating26.8 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 span35 ft (10.7 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2024)
Projected traffic33 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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$211,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Iris ST over Long Br built?

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

What condition is Iris ST over Long Br 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 Long Br carry?

About 30 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Iris ST over Long Br?

The structure is 35 ft (10.7 m) long with a longest span of 35 ft (10.7 m) and a deck 18 ft wide.

Who owns Iris ST over Long Br?

It is owned by the County Highway Agency.