US Bridges

FM 500th ST over Br Dirty Face CR

Fair

Johnson County, Iowa · 078071409 · Structure no. 000000000203481

Built
1977
48 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete Continuous
Length
91 ft
3 main spans
Daily traffic
270
2021 count
Owner
County
County Highway Agency

About this bridge

FM 500th ST over Br Dirty Face CR is a concrete continuous slab carrying FM 500th ST over Br Dirty Face CR in Johnson County, Iowa. It was built in 1977, so it is 48 years old, older 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 270 vehicles a day, roughly 20% of them trucks, projected to reach 270 by 2043. The structure is 91 ft (27.7 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesFM 500th ST
CrossesBr Dirty Face CR
Location078071409
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.5616, -91.61779
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.4 US tons
Inventory rating33.4 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length91 ft (27.7 m)
Longest span34 ft (10.4 m)
Deck width32 ft (9.9 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic270 (2021)
Projected traffic270 by 2043
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 FM 500th ST over Br Dirty Face CR built?

It was built in 1977, making it 48 years old in 2025.

What condition is FM 500th ST over Br Dirty Face 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 2023.

How much traffic does FM 500th ST over Br Dirty Face CR carry?

About 270 vehicles per day (2021 count), of which roughly 20% are trucks.

How long is FM 500th ST over Br Dirty Face CR?

The structure is 91 ft (27.7 m) long with a longest span of 34 ft (10.4 m) and a deck 32 ft wide.

Who owns FM 500th ST over Br Dirty Face CR?

It is owned by the County Highway Agency.