US Bridges

County RD 429 over Wyaconda Rvr

PoorClosed to traffic

Lewis County, Missouri · S 17 T 62 N R 6 W · Structure no. 16480

Built
1910
115 years old
Condition
Poor
inspected January 2018
Type
Truss - Thru
Steel
Length
76 ft
1 main span
Daily traffic
50
2024 count
Owner
County
County Highway Agency

About this bridge

County RD 429 over Wyaconda Rvr is a steel truss - thru carrying County RD 429 over Wyaconda Rvr in Lewis 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 4 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: closed to all traffic.

It carries about 50 vehicles a day, roughly 10% of them trucks, projected to reach 63 by 2044. The structure is 76 ft (23.2 m) long and 12 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

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CarriesCounty RD 429
CrossesWyaconda Rvr
LocationS 17 T 62 N R 6 W
RouteCounty Highway 122
CountyLewis County
StateMissouri
Coordinates40.16825, -91.58644
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2018
Inspection intervalevery 24 months
Operating statusClosed to all traffic
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation0: Immediate repair necessary to put back in service
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 alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating0 US tons
Inventory rating0 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1
Design loadOther
Structure length76 ft (23.2 m)
Longest span75 ft (22.9 m)
Deck width12 ft (3.7 m)
Roadway width12 ft (3.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2024)
Projected traffic63 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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$583,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 429 over Wyaconda Rvr built?

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

What condition is County RD 429 over Wyaconda Rvr 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 January 2018.

How much traffic does County RD 429 over Wyaconda Rvr carry?

About 50 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County RD 429 over Wyaconda Rvr?

The structure is 76 ft (23.2 m) long with a longest span of 75 ft (22.9 m) and a deck 12 ft wide.

Who owns County RD 429 over Wyaconda Rvr?

It is owned by the County Highway Agency.