US Bridges

So. 6th St. over Linn Creek

Fair

Marshall County, Iowa · 083183400 · Structure no. 000000000503805

Built
1984
41 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
245 ft
3 main spans
Daily traffic
11,300
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

So. 6th St. over Linn Creek is a prestressed concrete stringer/multi-beam or girder carrying So. 6th St. over Linn Creek in Marshall County, Iowa. It was built in 1984, so it is 41 years old, younger 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 11,300 vehicles a day, roughly 2% of them trucks, projected to reach 11,300 by 2043. The structure is 245 ft (74.7 m) long and 69 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSo. 6th St.
CrossesLinn Creek
Location083183400
RouteCity Street 0
CountyMarshall County
StateIowa
Coordinates42.03703, -92.92187
Functional classUrban Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
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 geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating72.5 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length245 ft (74.7 m)
Longest span82 ft (25 m)
Deck width69 ft (21 m)
Roadway width54 ft (16.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,300 (2022)
Projected traffic11,300 by 2043
Trucks2%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was So. 6th St. over Linn Creek built?

It was built in 1984, making it 41 years old in 2025.

What condition is So. 6th 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 So. 6th St. over Linn Creek carry?

About 11,300 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is So. 6th St. over Linn Creek?

The structure is 245 ft (74.7 m) long with a longest span of 82 ft (25 m) and a deck 69 ft wide.

Who owns So. 6th St. over Linn Creek?

It is owned by the City or Municipal Highway Agency.