US Bridges

Local over Dm River

PoorPosted for load

Humboldt County, Iowa · 093280503 · Structure no. 000000000185150

Built
1911
114 years old
Condition
Poor
inspected November 2024
Type
Truss - Thru
Steel
Length
110 ft
1 main span
Daily traffic
60
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Dm River is a steel truss - thru carrying Local over Dm River in Humboldt County, Iowa. It was built in 1911, so it is 114 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. Its operating status is: posted for load restriction.

It carries about 60 vehicles a day, projected to reach 60 by 2044. The structure is 110 ft (33.5 m) long and 16 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesLocal
CrossesDm River
Location093280503
RouteCounty Highway 0
CountyHumboldt County
StateIowa
Coordinates42.89205, -94.18363
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating12.3 US tons
Inventory rating8.4 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1 (+1 approach)
Design loadUnknown
Structure length110 ft (33.5 m)
Longest span90 ft (27.4 m)
Deck width16 ft (4.8 m)
Roadway width16 ft (4.8 m)
Vertical clearance over deck11 ft (3.3 m)

Traffic and service

Average daily traffic60 (2022)
Projected traffic60 by 2044
Trucks0%
Lanes on structure2
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Local over Dm River built?

It was built in 1911, making it 114 years old in 2025.

What condition is Local over Dm River 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 Local over Dm River carry?

About 60 vehicles per day (2022 count).

How long is Local over Dm River?

The structure is 110 ft (33.5 m) long with a longest span of 90 ft (27.4 m) and a deck 16 ft wide.

Who owns Local over Dm River?

It is owned by the County Highway Agency.