US Bridges

Unity Avenue over Branch of Silver Creek

Poor

Howard County, Iowa · 099110902 · Structure no. 000000000364530

Built
1960
65 years old
Condition
Poor
inspected April 2023
Type
Culvert
Wood or Timber
Length
25 ft
3 main spans
Daily traffic
21
2022 count
Owner
County
County Highway Agency

About this bridge

Unity Avenue over Branch of Silver Creek is a wood or timber culvert carrying Unity Avenue over Branch of Silver Creek in Howard County, Iowa. It was built in 1960, so it is 65 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 21 vehicles a day, projected to reach 21 by 2043. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesUnity Avenue
CrossesBranch of Silver Creek
Location099110902
RouteCounty Highway 0
CountyHoward County
StateIowa
Coordinates43.40428, -92.15983
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating21.9 US tons
Inventory rating16.2 US tons

Structure

Structure typeCulvert
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span8 ft (2.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21 (2022)
Projected traffic21 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Unity Avenue over Branch of Silver Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Unity Avenue over Branch of Silver Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.

How much traffic does Unity Avenue over Branch of Silver Creek carry?

About 21 vehicles per day (2022 count).

How long is Unity Avenue over Branch of Silver Creek?

The structure is 25 ft (7.6 m) long with a longest span of 8 ft (2.4 m).

Who owns Unity Avenue over Branch of Silver Creek?

It is owned by the County Highway Agency.