US Bridges

Rt Bb S over Isum CR

Fair

Jefferson County, Missouri · S 30 T 42 N R 4 E · Structure no. 8391

Built
1966
59 years old
Condition
Fair
inspected December 2024
Type
Culvert
Concrete Continuous
Length
40 ft
2 main spans
Daily traffic
1,437
2024 count
Owner
State
State Highway Agency

About this bridge

Rt Bb S over Isum CR is a concrete continuous culvert carrying Rt Bb S over Isum CR in Jefferson 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 1,437 vehicles a day, roughly 5% of them trucks, projected to reach 2,587 by 2044. The structure is 40 ft (12.3 m) long and 39 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesRt Bb S
CrossesIsum CR
LocationS 30 T 42 N R 4 E
RouteState Highway 0BB
CountyJefferson County
StateMissouri
Coordinates38.34241, -90.62647
Functional classRural Major Collector

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 inspectionDecember 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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating91.3 US tons
Inventory rating54.6 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
Structure length40 ft (12.3 m)
Longest span14 ft (4.3 m)
Deck width39 ft (11.9 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,437 (2024)
Projected traffic2,587 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Rt Bb S over Isum CR built?

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

What condition is Rt Bb S over Isum 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 December 2024.

How much traffic does Rt Bb S over Isum CR carry?

About 1,437 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Rt Bb S over Isum CR?

The structure is 40 ft (12.3 m) long with a longest span of 14 ft (4.3 m) and a deck 39 ft wide.

Who owns Rt Bb S over Isum CR?

It is owned by the State Highway Agency.