US Bridges

Nation RD over Rock CR

Fair

Clay County, Missouri · S 4 T 52 N R 31 W · Structure no. 16886

Built
1925
100 years old, rebuilt 1981
Condition
Fair
inspected January 2024
Type
Channel Beam
Concrete
Length
75 ft
1 main span
Daily traffic
471
2024 count
Owner
County
County Highway Agency

About this bridge

Nation RD over Rock CR is a concrete channel beam carrying Nation RD over Rock CR in Clay County, Missouri. It was built in 1925 and reconstructed in 1981, 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 471 vehicles a day, roughly 10% of them trucks, projected to reach 730 by 2044. The structure is 75 ft (22.9 m) long and 18 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesNation RD
CrossesRock CR
LocationS 4 T 52 N R 31 W
RouteCounty Highway 135
CountyClay County
StateMissouri
Coordinates39.3433, -94.39036
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating62.5 US tons
Inventory rating28.8 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length75 ft (22.9 m)
Longest span75 ft (22.9 m)
Deck width18 ft (5.6 m)
Roadway width18 ft (5.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic471 (2024)
Projected traffic730 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$572,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nation RD over Rock CR built?

It was built in 1925, making it 100 years old in 2025. It was reconstructed in 1981.

What condition is Nation RD over Rock 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 January 2024.

How much traffic does Nation RD over Rock CR carry?

About 471 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Nation RD over Rock CR?

The structure is 75 ft (22.9 m) long with a longest span of 75 ft (22.9 m) and a deck 18 ft wide.

Who owns Nation RD over Rock CR?

It is owned by the County Highway Agency.