US Bridges

120th Street over Simmons Creek

Good

Clinton County, Iowa · 083E51601 · Structure no. 000000000125472

Built
1993
32 years old
Condition
Good
inspected January 2025
Type
Tee Beam
Prestressed Concrete
Length
56 ft
1 main span
Daily traffic
62
2022 count
Owner
County
County Highway Agency

About this bridge

120th Street over Simmons Creek is a prestressed concrete tee beam carrying 120th Street over Simmons Creek in Clinton County, Iowa. It was built in 1993, so it is 32 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 62 vehicles a day, projected to reach 62 by 2045. The structure is 56 ft (17.1 m) long and 24 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Carries120th Street
CrossesSimmons Creek
Location083E51601
RouteCounty Highway 0
StateIowa
Coordinates42.00398, -90.37717
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJanuary 2025
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65.4 US tons
Inventory rating44.2 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length56 ft (17.1 m)
Longest span55 ft (16.8 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (7.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic62 (2022)
Projected traffic62 by 2045
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 120th Street over Simmons Creek built?

It was built in 1993, making it 32 years old in 2025.

What condition is 120th Street over Simmons Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2025.

How much traffic does 120th Street over Simmons Creek carry?

About 62 vehicles per day (2022 count).

How long is 120th Street over Simmons Creek?

The structure is 56 ft (17.1 m) long with a longest span of 55 ft (16.8 m) and a deck 24 ft wide.

Who owns 120th Street over Simmons Creek?

It is owned by the County Highway Agency.