US Bridges

Ansborough Ave over Trib to Miller Creek

Poor

Black Hawk County, Iowa · 87-13-28-02-10 · Structure no. 000000000074445

Built
1978
47 years old
Condition
Poor
inspected November 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
36 ft
2 main spans
Daily traffic
11
2022 count
Owner
County
County Highway Agency

About this bridge

Ansborough Ave over Trib to Miller Creek is a wood or timber stringer/multi-beam or girder carrying Ansborough Ave over Trib to Miller Creek in Black Hawk County, Iowa. It was built in 1978, so it is 47 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 11 vehicles a day, projected to reach 11 by 2043. The structure is 36 ft (11 m) long and 25 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesAnsborough Ave
CrossesTrib to Miller Creek
Location87-13-28-02-10
RouteCounty Highway 0
CountyBlack Hawk County
StateIowa
Coordinates42.32594, -92.37702
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 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
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating47.5 US tons
Inventory rating38 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadHS 20
Structure length36 ft (11 m)
Longest span17 ft (5.2 m)
Deck width25 ft (7.7 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11 (2022)
Projected traffic11 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ansborough Ave over Trib to Miller Creek built?

It was built in 1978, making it 47 years old in 2025.

What condition is Ansborough Ave over Trib to Miller 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 November 2023.

How much traffic does Ansborough Ave over Trib to Miller Creek carry?

About 11 vehicles per day (2022 count).

How long is Ansborough Ave over Trib to Miller Creek?

The structure is 36 ft (11 m) long with a longest span of 17 ft (5.2 m) and a deck 25 ft wide.

Who owns Ansborough Ave over Trib to Miller Creek?

It is owned by the County Highway Agency.