US Bridges

SW Obsrvtry Ave over Stream

Fair

Johnson County, Iowa · 078063306 · Structure no. 000000000203421

Built
1973
52 years old
Condition
Fair
inspected April 2023
Type
Channel Beam
Concrete
Length
37 ft
1 main span
Daily traffic
72
2021 count
Owner
County
County Highway Agency

About this bridge

SW Obsrvtry Ave over Stream is a concrete channel beam carrying SW Obsrvtry Ave over Stream in Johnson 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 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 72 vehicles a day, projected to reach 72 by 2043. The structure is 37 ft (11.3 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSW Obsrvtry Ave
CrossesStream
Location078063306
RouteCounty Highway 0
CountyJohnson County
StateIowa
Coordinates41.51902, -91.56037
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.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61 US tons
Inventory rating34 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length37 ft (11.3 m)
Longest span35 ft (10.7 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic72 (2021)
Projected traffic72 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 SW Obsrvtry Ave over Stream built?

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

What condition is SW Obsrvtry Ave over Stream 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 SW Obsrvtry Ave over Stream carry?

About 72 vehicles per day (2021 count).

How long is SW Obsrvtry Ave over Stream?

The structure is 37 ft (11.3 m) long with a longest span of 35 ft (10.7 m) and a deck 26 ft wide.

Who owns SW Obsrvtry Ave over Stream?

It is owned by the County Highway Agency.