US Bridges

J 20 Agency RD over Spillway

Fair

Des Moines County, Iowa · 069050103 · Structure no. 000000000699580

Built
1935
90 years old, rebuilt 2004
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
64 ft
1 main span
Daily traffic
400
2022 count
Owner
County
County Highway Agency

About this bridge

J 20 Agency RD over Spillway is a steel stringer/multi-beam or girder carrying J 20 Agency RD over Spillway in Des Moines County, Iowa. It was built in 1935 and reconstructed in 2004, so it is 90 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 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 400 vehicles a day, roughly 13% of them trucks, projected to reach 400 by 2043. The structure is 64 ft (19.5 m) long and 27 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesJ 20 Agency RD
CrossesSpillway
Location069050103
RouteCounty Highway 0
CountyDes Moines County
StateIowa
Coordinates40.81, -91.38719
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
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 evaluation6: Equal to 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 alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating44.1 US tons
Inventory rating23.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length64 ft (19.5 m)
Longest span61 ft (18.6 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2022)
Projected traffic400 by 2043
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was J 20 Agency RD over Spillway built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 2004.

What condition is J 20 Agency RD over Spillway 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 September 2023.

How much traffic does J 20 Agency RD over Spillway carry?

About 400 vehicles per day (2022 count), of which roughly 13% are trucks.

How long is J 20 Agency RD over Spillway?

The structure is 64 ft (19.5 m) long with a longest span of 61 ft (18.6 m) and a deck 27 ft wide.

Who owns J 20 Agency RD over Spillway?

It is owned by the County Highway Agency.