US Bridges

CO RD NE 121 over Flagstaff CR

Fair

Johnson County, Missouri · S 6 T 47 N R 25 W · Structure no. 16671

Built
1982
43 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
31 ft
1 main span
Daily traffic
60
2023 count
Owner
County
County Highway Agency

About this bridge

CO RD NE 121 over Flagstaff CR is a steel stringer/multi-beam or girder carrying CO RD NE 121 over Flagstaff CR in Johnson County, Missouri. It was built in 1982, so it is 43 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 6 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 60 vehicles a day, roughly 10% of them trucks, projected to reach 96 by 2043. The structure is 31 ft (9.4 m) long and 21 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesCO RD NE 121
CrossesFlagstaff CR
LocationS 6 T 47 N R 25 W
RouteCounty Highway 128
CountyJohnson County
StateMissouri
Coordinates38.90151, -93.71345
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating34.7 US tons
Inventory rating19.8 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 width21 ft (6.3 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic60 (2023)
Projected traffic96 by 2043
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 CO RD NE 121 over Flagstaff CR built?

It was built in 1982, making it 43 years old in 2025.

What condition is CO RD NE 121 over Flagstaff 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 November 2024.

How much traffic does CO RD NE 121 over Flagstaff CR carry?

About 60 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is CO RD NE 121 over Flagstaff CR?

The structure is 31 ft (9.4 m) long with a longest span of 30 ft (9.1 m) and a deck 21 ft wide.

Who owns CO RD NE 121 over Flagstaff CR?

It is owned by the County Highway Agency.