US Bridges

FM-310th Street over Iais RR

PoorPosted for load

Pottawattamie County, Iowa · 076412002 · Structure no. 000000000288430

Built
1952
73 years old
Condition
Poor
inspected April 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
124 ft
7 main spans
Daily traffic
110
2022 count
Owner
County
County Highway Agency

About this bridge

FM-310th Street over Iais RR is a wood or timber stringer/multi-beam or girder carrying FM-310th Street over Iais RR in Pottawattamie County, Iowa. It was built in 1952, so it is 73 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 110 vehicles a day, projected to reach 110 by 2043. The structure is 124 ft (37.8 m) long and 24 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesFM-310th Street
CrossesIais RR
Location076412002
RouteCounty Highway 0
CountyPottawattamie County
StateIowa
Coordinates41.37167, -95.59444
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating30.6 US tons
Inventory rating21.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans7
Design loadHS 20
Structure length124 ft (37.8 m)
Longest span22 ft (6.7 m)
Deck width24 ft (7.2 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2022)
Projected traffic110 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was FM-310th Street over Iais RR built?

It was built in 1952, making it 73 years old in 2025.

What condition is FM-310th Street over Iais RR 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 April 2024.

How much traffic does FM-310th Street over Iais RR carry?

About 110 vehicles per day (2022 count).

How long is FM-310th Street over Iais RR?

The structure is 124 ft (37.8 m) long with a longest span of 22 ft (6.7 m) and a deck 24 ft wide.

Who owns FM-310th Street over Iais RR?

It is owned by the County Highway Agency.