US Bridges

FM 120th ST over Br Plum CR

Fair

Johnson County, Iowa · 081081201 · Structure no. 000000000205791

Built
1989
36 years old
Condition
Fair
inspected April 2021
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
1,630
2022 count
Owner
County
County Highway Agency

About this bridge

FM 120th ST over Br Plum CR is a concrete continuous culvert carrying FM 120th ST over Br Plum CR in Johnson County, Iowa. It was built in 1989, so it is 36 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 6 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 1,630 vehicles a day, roughly 19% of them trucks, projected to reach 1,630 by 2043. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFM 120th ST
CrossesBr Plum CR
Location081081201
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.84744, -91.72269
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHL 93
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,630 (2022)
Projected traffic1,630 by 2043
Trucks19%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 120th ST over Br Plum CR built?

It was built in 1989, making it 36 years old in 2025.

What condition is FM 120th ST over Br Plum 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 April 2021.

How much traffic does FM 120th ST over Br Plum CR carry?

About 1,630 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is FM 120th ST over Br Plum CR?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m).

Who owns FM 120th ST over Br Plum CR?

It is owned by the County Highway Agency.