US Bridges

M16 370th ST over Nishnabotna River

Good

Mills County, Iowa · 073402904 · Structure no. 000000000246631

Built
2018
7 years old
Condition
Good
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
312 ft
3 main spans
Daily traffic
214
2021 count
Owner
County
County Highway Agency

About this bridge

M16 370th ST over Nishnabotna River is a prestressed concrete stringer/multi-beam or girder carrying M16 370th ST over Nishnabotna River in Mills County, Iowa. It was built in 2018, so it is 7 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 214 vehicles a day, roughly 14% of them trucks, projected to reach 214 by 2043. The structure is 312 ft (95.1 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesM16 370th ST
CrossesNishnabotna River
Location073402904
RouteCounty Highway 0
CountyMills County
StateIowa
Coordinates41.08867, -95.4804
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating37.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length312 ft (95.1 m)
Longest span107 ft (32.6 m)
Deck width33 ft (10.1 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic214 (2021)
Projected traffic214 by 2043
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 M16 370th ST over Nishnabotna River built?

It was built in 2018, making it 7 years old in 2025.

What condition is M16 370th ST over Nishnabotna River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in March 2023.

How much traffic does M16 370th ST over Nishnabotna River carry?

About 214 vehicles per day (2021 count), of which roughly 14% are trucks.

How long is M16 370th ST over Nishnabotna River?

The structure is 312 ft (95.1 m) long with a longest span of 107 ft (32.6 m) and a deck 33 ft wide.

Who owns M16 370th ST over Nishnabotna River?

It is owned by the County Highway Agency.