US Bridges

120th ST over Drainage

Good

Plymouth County, Iowa · 93-48-13-01-10-40 · Structure no. 000000000277591

Built
2013
12 years old
Condition
Good
inspected September 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
41 ft
1 main span
Daily traffic
26
2022 count
Owner
County
County Highway Agency

About this bridge

120th ST over Drainage is a concrete stringer/multi-beam or girder carrying 120th ST over Drainage in Plymouth County, Iowa. It was built in 2013, so it is 12 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 26 vehicles a day, projected to reach 26 by 2043. The structure is 41 ft (12.6 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries120th ST
CrossesDrainage
Location93-48-13-01-10-40
RouteCounty Highway 0
CountyPlymouth County
StateIowa
Coordinates42.88025, -96.46162
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 protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64.3 US tons
Inventory rating49.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length41 ft (12.6 m)
Longest span39 ft (11.9 m)
Deck width31 ft (9.6 m)
Roadway width31 ft (9.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic26 (2022)
Projected traffic26 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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$360,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 120th ST over Drainage built?

It was built in 2013, making it 12 years old in 2025.

What condition is 120th ST over Drainage 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 September 2023.

How much traffic does 120th ST over Drainage carry?

About 26 vehicles per day (2022 count).

How long is 120th ST over Drainage?

The structure is 41 ft (12.6 m) long with a longest span of 39 ft (11.9 m) and a deck 31 ft wide.

Who owns 120th ST over Drainage?

It is owned by the County Highway Agency.