US Bridges

120th ST over Stream

PoorPosted for load

Johnson County, Iowa · 081050901 · Structure no. 000000000205300

Built
1952
73 years old
Condition
Poor
inspected April 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
42 ft
2 main spans
Daily traffic
30
2021 count
Owner
County
County Highway Agency

About this bridge

120th ST over Stream is a wood or timber stringer/multi-beam or girder carrying 120th ST over Stream in Johnson County, Iowa. It was built in 1952, so it is 73 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 30 vehicles a day, projected to reach 30 by 2043. The structure is 42 ft (12.8 m) long and 16 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
Carries120th ST
CrossesStream
Location081050901
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.84561, -91.42621
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry8: Equal to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating28.1 US tons
Inventory rating20.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span19 ft (5.8 m)
Deck width16 ft (4.8 m)
Roadway width16 ft (4.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2021)
Projected traffic30 by 2043
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 120th ST over Stream built?

It was built in 1952, making it 73 years old in 2025.

What condition is 120th ST over Stream in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.

How much traffic does 120th ST over Stream carry?

About 30 vehicles per day (2021 count).

How long is 120th ST over Stream?

The structure is 42 ft (12.8 m) long with a longest span of 19 ft (5.8 m) and a deck 16 ft wide.

Who owns 120th ST over Stream?

It is owned by the County Highway Agency.