US Bridges

CO RD NW 550 over Br S Fk Blackwater

Fair

Johnson County, Missouri · S 30 T 47 N R 28 W · Structure no. 13571

Built
1925
100 years old
Condition
Fair
inspected November 2024
Type
Culvert
Concrete
Length
26 ft
2 main spans
Daily traffic
110
2023 count
Owner
County
County Highway Agency

About this bridge

CO RD NW 550 over Br S Fk Blackwater is a concrete culvert carrying CO RD NW 550 over Br S Fk Blackwater in Johnson County, Missouri. It was built in 1925, so it is 100 years old, older 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 110 vehicles a day, roughly 10% of them trucks, projected to reach 176 by 2043. The structure is 26 ft (7.9 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesCO RD NW 550
CrossesBr S Fk Blackwater
LocationS 30 T 47 N R 28 W
RouteCounty Highway 42
CountyJohnson County
StateMissouri
Coordinates38.8552, -94.04661
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
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.6 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadOther
Structure length26 ft (7.9 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2023)
Projected traffic176 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 NW 550 over Br S Fk Blackwater built?

It was built in 1925, making it 100 years old in 2025.

What condition is CO RD NW 550 over Br S Fk Blackwater 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 NW 550 over Br S Fk Blackwater carry?

About 110 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is CO RD NW 550 over Br S Fk Blackwater?

The structure is 26 ft (7.9 m) long with a longest span of 12 ft (3.7 m).

Who owns CO RD NW 550 over Br S Fk Blackwater?

It is owned by the County Highway Agency.