US Bridges

County RD 478 over Black CR

PoorPosted for load

Shelby County, Missouri · S 29 T 57 N R 9 W · Structure no. 22070

Built
1910
115 years old
Condition
Poor
inspected March 2024
Type
Truss - Thru
Steel
Length
61 ft
1 main span
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

County RD 478 over Black CR is a steel truss - thru carrying County RD 478 over Black CR in Shelby County, Missouri. It was built in 1910, so it is 115 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 35 vehicles a day, roughly 10% of them trucks, projected to reach 44 by 2044. The structure is 61 ft (18.6 m) long and 11 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCounty RD 478
CrossesBlack CR
LocationS 29 T 57 N R 9 W
RouteCounty Highway 339
CountyShelby County
StateMissouri
Coordinates39.70275, -91.92208
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating13.9 US tons
Inventory rating8.9 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length61 ft (18.6 m)
Longest span60 ft (18.3 m)
Deck width11 ft (3.5 m)
Roadway width11 ft (3.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic44 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$472,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 478 over Black CR built?

It was built in 1910, making it 115 years old in 2025.

What condition is County RD 478 over Black CR in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in March 2024.

How much traffic does County RD 478 over Black CR carry?

About 35 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County RD 478 over Black CR?

The structure is 61 ft (18.6 m) long with a longest span of 60 ft (18.3 m) and a deck 11 ft wide.

Who owns County RD 478 over Black CR?

It is owned by the County Highway Agency.