US Bridges

Ia 415 over Saylorville Reservoir

Fair

Polk County, Iowa · West of Polk City · Structure no. 000000000361170

Built
1973
52 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
4,933 ft
25 main spans
Daily traffic
10,100
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 415 over Saylorville Reservoir is a steel continuous stringer/multi-beam or girder carrying Ia 415 over Saylorville Reservoir in Polk County, Iowa. It was built in 1973, so it is 52 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 10,100 vehicles a day, roughly 3% of them trucks, projected to reach 10,100 by 2044. The structure is 4,933 ft (1,503.6 m) long and 32 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesIa 415
CrossesSaylorville Reservoir
LocationWest of Polk City
RouteState Highway 415
CountyPolk County
StateIowa
Coordinates41.76363, -93.73231
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating68 US tons
Inventory rating40.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans25
Design loadH 20
Structure length4,933 ft (1,503.6 m)
Longest span216 ft (65.8 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,100 (2022)
Projected traffic10,100 by 2044
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ia 415 over Saylorville Reservoir built?

It was built in 1973, making it 52 years old in 2025.

What condition is Ia 415 over Saylorville Reservoir 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 2024.

How much traffic does Ia 415 over Saylorville Reservoir carry?

About 10,100 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is Ia 415 over Saylorville Reservoir?

The structure is 4,933 ft (1,503.6 m) long with a longest span of 216 ft (65.8 m) and a deck 32 ft wide.

Who owns Ia 415 over Saylorville Reservoir?

It is owned by the State Highway Agency.