US Bridges

S 12th ST over Linn Creek

Fair

Marshall County, Iowa · 084183402 · Structure no. 000000000007880

Built
1967
58 years old
Condition
Fair
inspected July 2023
Type
Slab
Concrete Continuous
Length
127 ft
3 main spans
Daily traffic
1,280
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

S 12th ST over Linn Creek is a concrete continuous slab carrying S 12th ST over Linn Creek in Marshall County, Iowa. It was built in 1967, so it is 58 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 5 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 1,280 vehicles a day, projected to reach 1,280 by 2043. The structure is 127 ft (38.7 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesS 12th ST
CrossesLinn Creek
Location084183402
RouteCity Street 0
CountyMarshall County
StateIowa
Coordinates42.0349, -92.93192
Functional classUrban 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating57.5 US tons
Inventory rating33.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length127 ft (38.7 m)
Longest span49 ft (14.9 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,280 (2022)
Projected traffic1,280 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

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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$250,000
NavigationNo navigation control on waterway

Frequently asked questions

When was S 12th ST over Linn Creek built?

It was built in 1967, making it 58 years old in 2025.

What condition is S 12th ST over Linn Creek 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 July 2023.

How much traffic does S 12th ST over Linn Creek carry?

About 1,280 vehicles per day (2022 count).

How long is S 12th ST over Linn Creek?

The structure is 127 ft (38.7 m) long with a longest span of 49 ft (14.9 m) and a deck 30 ft wide.

Who owns S 12th ST over Linn Creek?

It is owned by the City or Municipal Highway Agency.