US Bridges

County RD 550 over Alder Br

FairPosted for load

Cedar County, Missouri · S 9 T 35 N R 28 W · Structure no. 15108

Built
1950
75 years old, rebuilt 1981
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
22 ft
1 main span
Daily traffic
100
2023 count
Owner
County
County Highway Agency

About this bridge

County RD 550 over Alder Br is a steel stringer/multi-beam or girder carrying County RD 550 over Alder Br in Cedar County, Missouri. It was built in 1950 and reconstructed in 1981, so it is 75 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. Its operating status is: posted for load restriction.

It carries about 100 vehicles a day, roughly 10% of them trucks, projected to reach 125 by 2043. The structure is 22 ft (6.7 m) long and 14 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesCounty RD 550
CrossesAlder Br
LocationS 9 T 35 N R 28 W
RouteCounty Highway 85
CountyCedar County
StateMissouri
Coordinates37.81926, -94.01777
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionDecember 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating14.9 US tons
Inventory rating7.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length22 ft (6.7 m)
Longest span21 ft (6.4 m)
Deck width14 ft (4.3 m)
Roadway width13 ft (4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2023)
Projected traffic125 by 2043
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$239,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 550 over Alder Br built?

It was built in 1950, making it 75 years old in 2025. It was reconstructed in 1981.

What condition is County RD 550 over Alder Br 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 2024.

How much traffic does County RD 550 over Alder Br carry?

About 100 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is County RD 550 over Alder Br?

The structure is 22 ft (6.7 m) long with a longest span of 21 ft (6.4 m) and a deck 14 ft wide.

Who owns County RD 550 over Alder Br?

It is owned by the County Highway Agency.