US Bridges

310th ST over Stream

Poor

Mills County, Iowa · 071413202 · Structure no. 000000000245180

Built
1960
65 years old
Condition
Poor
inspected March 2023
Type
Slab
Concrete
Length
26 ft
1 main span
Daily traffic
325
2021 count
Owner
County
County Highway Agency

About this bridge

310th ST over Stream is a concrete slab carrying 310th ST over Stream in Mills County, Iowa. It was built in 1960, so it is 65 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.

It carries about 325 vehicles a day, roughly 17% of them trucks, projected to reach 325 by 2043. The structure is 26 ft (7.9 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries310th ST
CrossesStream
Location071413202
RouteCounty Highway 0
CountyMills County
StateIowa
Coordinates40.91202, -95.59449
Functional classRural Major 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
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58.1 US tons
Inventory rating34.6 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length26 ft (7.9 m)
Longest span24 ft (7.3 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic325 (2021)
Projected traffic325 by 2043
Trucks17%
Lanes on structure2
Traffic directionTwo-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 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 310th ST over Stream built?

It was built in 1960, making it 65 years old in 2025.

What condition is 310th ST over Stream 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 March 2023.

How much traffic does 310th ST over Stream carry?

About 325 vehicles per day (2021 count), of which roughly 17% are trucks.

How long is 310th ST over Stream?

The structure is 26 ft (7.9 m) long with a longest span of 24 ft (7.3 m) and a deck 30 ft wide.

Who owns 310th ST over Stream?

It is owned by the County Highway Agency.