US Bridges

CO RD NW21 over Trib of Flagstaff

Fair

Johnson County, Missouri · S 26 T 48 N R 26 W · Structure no. 16415

Built
1996
29 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
35 ft
1 main span
Daily traffic
25
2023 count
Owner
County
County Highway Agency

About this bridge

CO RD NW21 over Trib of Flagstaff is a steel stringer/multi-beam or girder carrying CO RD NW21 over Trib of Flagstaff in Johnson County, Missouri. It was built in 1996, so it is 29 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 25 vehicles a day, roughly 10% of them trucks, projected to reach 40 by 2043. The structure is 35 ft (10.7 m) long and 23 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesCO RD NW21
CrossesTrib of Flagstaff
LocationS 26 T 48 N R 26 W
RouteCounty Highway 119
CountyJohnson County
StateMissouri
Coordinates38.9224, -93.74258
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 rating61.5 US tons
Inventory rating36.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length35 ft (10.7 m)
Longest span33 ft (10.1 m)
Deck width23 ft (6.9 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25 (2023)
Projected traffic40 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 NW21 over Trib of Flagstaff built?

It was built in 1996, making it 29 years old in 2025.

What condition is CO RD NW21 over Trib of Flagstaff 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 NW21 over Trib of Flagstaff carry?

About 25 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is CO RD NW21 over Trib of Flagstaff?

The structure is 35 ft (10.7 m) long with a longest span of 33 ft (10.1 m) and a deck 23 ft wide.

Who owns CO RD NW21 over Trib of Flagstaff?

It is owned by the County Highway Agency.