US Bridges

Local over Dm River

PoorPosted for load

Humboldt County, Iowa · 093280602 · Structure no. 000000000185160

Built
1924
101 years old
Condition
Poor
inspected November 2024
Type
Truss - Thru
Steel
Length
122 ft
1 main span
Daily traffic
11
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 1924, so it is 101 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 11 vehicles a day, projected to reach 11 by 2044. The structure is 122 ft (37.2 m) long and 18 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesLocal
CrossesDm River
Location093280602
RouteCounty Highway 0
CountyHumboldt County
StateIowa
Coordinates42.90426, -94.20769
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating18 US tons
Inventory rating11.5 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length122 ft (37.2 m)
Longest span120 ft (36.6 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.2 m)
Vertical clearance over deck10 ft (3.1 m)

Traffic and service

Average daily traffic11 (2022)
Projected traffic11 by 2044
Trucks0%
Lanes on structure2
Traffic directionOne-lane bridge for two-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 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 1924, making it 101 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 11 vehicles per day (2022 count).

How long is Local over Dm River?

The structure is 122 ft (37.2 m) long with a longest span of 120 ft (36.6 m) and a deck 18 ft wide.

Who owns Local over Dm River?

It is owned by the County Highway Agency.