US Bridges

120 ST over Rock CR

Fair

Atchison County, Missouri · S 4 T 66 N R 40 W · Structure no. 15015

Built
1991
34 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
139 ft
3 main spans
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

120 ST over Rock CR is a steel stringer/multi-beam or girder carrying 120 ST over Rock CR in Atchison County, Missouri. It was built in 1991, so it is 34 years old, younger 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 10% of them trucks, projected to reach 40 by 2044. The structure is 139 ft (42.4 m) long and 25 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries120 ST
CrossesRock CR
LocationS 4 T 66 N R 40 W
RouteCounty Highway 82
CountyAtchison County
StateMissouri
Coordinates40.55357, -95.43654
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionFebruary 2024
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating86.3 US tons
Inventory rating39.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadOther
Structure length139 ft (42.4 m)
Longest span74 ft (22.7 m)
Deck width25 ft (7.6 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic40 by 2044
Trucks10%
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 120 ST over Rock CR built?

It was built in 1991, making it 34 years old in 2025.

What condition is 120 ST over Rock 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 February 2024.

How much traffic does 120 ST over Rock CR carry?

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

How long is 120 ST over Rock CR?

The structure is 139 ft (42.4 m) long with a longest span of 74 ft (22.7 m) and a deck 25 ft wide.

Who owns 120 ST over Rock CR?

It is owned by the County Highway Agency.