US Bridges

Lantern Ave over Mill Creek

Poor

Clayton County, Iowa · 091031306 · Structure no. 000000000361830

Built
1940
85 years old, rebuilt 2006
Condition
Poor
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
22 ft
1 main span
Daily traffic
11
2022 count
Owner
County
County Highway Agency

About this bridge

Lantern Ave over Mill Creek is a steel stringer/multi-beam or girder carrying Lantern Ave over Mill Creek in Clayton County, Iowa. It was built in 1940 and reconstructed in 2006, so it is 85 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 2044. The structure is 22 ft (6.7 m) long and 20 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesLantern Ave
CrossesMill Creek
Location091031306
RouteCounty Highway 0
CountyClayton County
StateIowa
Coordinates42.69684, -91.14727
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 6 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating70 US tons
Inventory rating53.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length22 ft (6.7 m)
Longest span20 ft (6.1 m)
Deck width20 ft (6.1 m)
Roadway width19 ft (5.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11 (2022)
Projected traffic11 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Lantern Ave over Mill Creek built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 2006.

What condition is Lantern Ave over Mill 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 2024.

How much traffic does Lantern Ave over Mill Creek carry?

About 11 vehicles per day (2022 count).

How long is Lantern Ave over Mill Creek?

The structure is 22 ft (6.7 m) long with a longest span of 20 ft (6.1 m) and a deck 20 ft wide.

Who owns Lantern Ave over Mill Creek?

It is owned by the County Highway Agency.