US Bridges

Rt Y S over N Blackbird CR

Fair

Putnam County, Missouri · S 29 T 66 N R 18 W · Structure no. 7923

Built
1955
70 years old, rebuilt 2020
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
113 ft
3 main spans
Daily traffic
104
2024 count
Owner
State
State Highway Agency

About this bridge

Rt Y S over N Blackbird CR is a steel stringer/multi-beam or girder carrying Rt Y S over N Blackbird CR in Putnam County, Missouri. It was built in 1955 and reconstructed in 2020, so it is 70 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 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 104 vehicles a day, roughly 13% of them trucks, projected to reach 130 by 2044. The structure is 113 ft (34.4 m) long and 22 ft wide. If it were closed, the detour would be 21.1 mi (34 km).

Location

Open in Google Maps
CarriesRt Y S
CrossesN Blackbird CR
LocationS 29 T 66 N R 18 W
RouteState Highway 0Y
CountyPutnam County
StateMissouri
Coordinates40.5008, -92.93742
Functional classRural Minor Collector

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.7 US tons
Inventory rating24.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 10
Structure length113 ft (34.4 m)
Longest span45 ft (13.8 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic104 (2024)
Projected traffic130 by 2044
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed21.1 mi (34 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Rt Y S over N Blackbird CR built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 2020.

What condition is Rt Y S over N Blackbird 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 December 2023.

How much traffic does Rt Y S over N Blackbird CR carry?

About 104 vehicles per day (2024 count), of which roughly 13% are trucks.

How long is Rt Y S over N Blackbird CR?

The structure is 113 ft (34.4 m) long with a longest span of 45 ft (13.8 m) and a deck 22 ft wide.

Who owns Rt Y S over N Blackbird CR?

It is owned by the State Highway Agency.