US Bridges

280th ST over Boone River

PoorClosed to traffic

Hamilton County, Iowa · 088253108 · Structure no. 000000000171920

Built
1902
123 years old, rebuilt 2008
Condition
Poor
inspected September 2020
Type
Truss - Thru
Steel
Length
186 ft
1 main span
Daily traffic
62
2022 count
Owner
County
County Highway Agency

About this bridge

280th ST over Boone River is a steel truss - thru carrying 280th ST over Boone River in Hamilton County, Iowa. It was built in 1902 and reconstructed in 2008, so it is 123 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 0 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: closed to all traffic.

It carries about 62 vehicles a day, projected to reach 62 by 2043. The structure is 186 ft (56.7 m) long and 16 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
Carries280th ST
CrossesBoone River
Location088253108
RouteCounty Highway 0
CountyHamilton County
StateIowa
Coordinates42.38643, -93.80923
Functional classRural Minor Collector

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
Deck0 FailedOut of service and beyond corrective action.
Superstructure0 FailedOut of service and beyond corrective action.
Substructure0 FailedOut of service and beyond corrective action.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2020
Inspection intervalevery 24 months
Operating statusClosed to all traffic
ScourFoundations stable; scour above top of footing
Structural evaluation0: Immediate repair necessary to put back in service
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating0 US tons
Inventory rating0 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1 (+1 approach)
Design loadUnknown
Structure length186 ft (56.7 m)
Longest span160 ft (48.8 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.4 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic62 (2022)
Projected traffic62 by 2043
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 280th ST over Boone River built?

It was built in 1902, making it 123 years old in 2025. It was reconstructed in 2008.

What condition is 280th ST over Boone 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 September 2020.

How much traffic does 280th ST over Boone River carry?

About 62 vehicles per day (2022 count).

How long is 280th ST over Boone River?

The structure is 186 ft (56.7 m) long with a longest span of 160 ft (48.8 m) and a deck 16 ft wide.

Who owns 280th ST over Boone River?

It is owned by the County Highway Agency.