US Bridges

470th ST over Montgomery Creek

Fair

Clay County, Iowa · 094361403 · Structure no. 000000000115861

Built
1998
27 years old
Condition
Fair
inspected March 2023
Type
Slab
Concrete
Length
30 ft
1 main span
Daily traffic
30
2022 count
Owner
County
County Highway Agency

About this bridge

470th ST over Montgomery Creek is a concrete slab carrying 470th ST over Montgomery Creek in Clay County, Iowa. It was built in 1998, so it is 27 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 6 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 30 vehicles a day, projected to reach 30 by 2043. The structure is 30 ft (9.1 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries470th ST
CrossesMontgomery Creek
Location094361403
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates42.96804, -95.05601
Functional classRural Local

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.1 US tons
Inventory rating32.5 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span29 ft (8.8 m)
Deck width30 ft (9.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2022)
Projected traffic30 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

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 470th ST over Montgomery Creek built?

It was built in 1998, making it 27 years old in 2025.

What condition is 470th ST over Montgomery 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 March 2023.

How much traffic does 470th ST over Montgomery Creek carry?

About 30 vehicles per day (2022 count).

How long is 470th ST over Montgomery Creek?

The structure is 30 ft (9.1 m) long with a longest span of 29 ft (8.8 m) and a deck 30 ft wide.

Who owns 470th ST over Montgomery Creek?

It is owned by the County Highway Agency.