US Bridges

SR F20 over I-29

Fair

Harrison County, Iowa · At Jct. of SR F20 · Structure no. 000000000028010

Built
1966
59 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
219 ft
4 main spans
Daily traffic
319
2022 count
Owner
State
State Highway Agency

About this bridge

SR F20 over I-29 is a prestressed concrete stringer/multi-beam or girder carrying SR F20 over I-29 in Harrison County, Iowa. It was built in 1966, so it is 59 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 319 vehicles a day, roughly 6% of them trucks, projected to reach 319 by 2044. The structure is 219 ft (66.8 m) long and 36 ft wide.

Location

Open in Google Maps
CarriesSR F20
CrossesI-29
LocationAt Jct. of SR F20
RouteCounty Highway 0
CountyHarrison County
StateIowa
Coordinates41.80185, -96.05584
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating72.6 US tons
Inventory rating43.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length219 ft (66.8 m)
Longest span69 ft (21 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic319 (2022)
Projected traffic319 by 2044
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR F20 over I-29 built?

It was built in 1966, making it 59 years old in 2025.

What condition is SR F20 over I-29 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 2024.

How much traffic does SR F20 over I-29 carry?

About 319 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is SR F20 over I-29?

The structure is 219 ft (66.8 m) long with a longest span of 69 ft (21 m) and a deck 36 ft wide.

Who owns SR F20 over I-29?

It is owned by the State Highway Agency.