US Bridges

Thunder RD over Knob CR

Fair

Cass County, Missouri · S 15 T 43 N R 29 W · Structure no. 25114

Built
1966
59 years old
Condition
Fair
inspected April 2023
Type
Culvert
Concrete
Length
22 ft
2 main spans
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

Thunder RD over Knob CR is a concrete culvert carrying Thunder RD over Knob CR in Cass County, Missouri. It was built in 1966, so it is 59 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 35 vehicles a day, roughly 5% of them trucks, projected to reach 56 by 2044. The structure is 22 ft (6.7 m) long and 26 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesThunder RD
CrossesKnob CR
LocationS 15 T 43 N R 29 W
RouteCounty Highway 629
CountyCass County
StateMissouri
Coordinates38.51631, -94.11237
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
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.6 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadH 15
Structure length22 ft (6.7 m)
Longest span11 ft (3.4 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic56 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Thunder RD over Knob CR built?

It was built in 1966, making it 59 years old in 2025.

What condition is Thunder RD over Knob 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 April 2023.

How much traffic does Thunder RD over Knob CR carry?

About 35 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Thunder RD over Knob CR?

The structure is 22 ft (6.7 m) long with a longest span of 11 ft (3.4 m) and a deck 26 ft wide.

Who owns Thunder RD over Knob CR?

It is owned by the County Highway Agency.