US Bridges

120th ST over Mud Creek

Fair

Woodbury County, Iowa · 089451303 · Structure no. 000000000355128

Built
1981
44 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
69 ft
2 main spans
Daily traffic
20
2022 count
Owner
County
County Highway Agency

About this bridge

120th ST over Mud Creek is a steel continuous stringer/multi-beam or girder carrying 120th ST over Mud Creek in Woodbury County, Iowa. It was built in 1981, so it is 44 years old, younger than the Iowa average of 45.5 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 20 vehicles a day, projected to reach 20 by 2044. The structure is 69 ft (21 m) long and 18 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries120th ST
CrossesMud Creek
Location089451303
RouteCounty Highway 0
CountyWoodbury County
StateIowa
Coordinates42.53277, -96.09855
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating42.3 US tons
Inventory rating30.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckWood or timber
Main spans2 (+2 approach)
Design loadHS 20
Structure length69 ft (21 m)
Longest span19 ft (5.8 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2022)
Projected traffic20 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 120th ST over Mud Creek built?

It was built in 1981, making it 44 years old in 2025.

What condition is 120th ST over Mud Creek 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 July 2024.

How much traffic does 120th ST over Mud Creek carry?

About 20 vehicles per day (2022 count).

How long is 120th ST over Mud Creek?

The structure is 69 ft (21 m) long with a longest span of 19 ft (5.8 m) and a deck 18 ft wide.

Who owns 120th ST over Mud Creek?

It is owned by the County Highway Agency.