Napoleon ST over Snyder Creek

Fair

Johnson County, Iowa · 078060101 · Structure no. 000000000203101

Built: 1987; 38 years old
Condition: Fair; inspected April 2021
Type: Slab; Concrete Continuous
Length: 128 ft; 3 main spans
Daily traffic: 381; 2022 count
Owner: County; County Highway Agency

About this bridge

Napoleon ST over Snyder Creek is a concrete continuous slab carrying Napoleon ST over Snyder Creek in Johnson County, Iowa. It was built in 1987, so it is 38 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 381 vehicles a day, projected to reach 381 by 2043. The structure is 128 ft (39 m) long and 27 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesNapoleon ST

CrossesSnyder Creek

Location078060101

RouteCounty Highway 0

CountyJohnson County

StateIowa

Coordinates41.59857, -91.50116

Functional classRural Local

Condition and inspection

Fair

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

Component	Rating	Meaning
Deck	6 Satisfactory	Structural elements show some minor deterioration.
Superstructure	6 Satisfactory	Structural elements show some minor deterioration.
Substructure	8 Very Good	No problems noted.
Channel and channel protection	6 Satisfactory	Structural 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

Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is

Waterway adequacy8: Equal to present desirable criteria

Approach roadway alignment8: Equal to present desirable criteria

Operating rating99 US tons

Inventory rating63.7 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadHS 20

Structure length128 ft (39 m)

Longest span50 ft (15.2 m)

Deck width27 ft (8.2 m)

Roadway width24 ft (7.3 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic381 (2022)

Projected traffic381 by 2043

Trucks0%

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 proposedReplacement because of substandard load-carrying capacity or roadway geometry

Estimated improvement cost—

NavigationNo navigation control on waterway

Frequently asked questions

When was Napoleon ST over Snyder Creek built?

It was built in 1987, making it 38 years old in 2025.

What condition is Napoleon ST over Snyder Creek 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 Napoleon ST over Snyder Creek carry?

About 381 vehicles per day (2022 count).

How long is Napoleon ST over Snyder Creek?

The structure is 128 ft (39 m) long with a longest span of 50 ft (15.2 m) and a deck 27 ft wide.

Who owns Napoleon ST over Snyder Creek?

It is owned by the County Highway Agency.