US Bridges

EB I-80 over 770th Street

Fair

Cass County, Iowa · 1.7 Mi. E of Ia 148 · Structure no. 000000000018210

Built
1958
67 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
162 ft
3 main spans
Daily traffic
11,650
2022 count
Owner
State
State Highway Agency

About this bridge

EB I-80 over 770th Street is a prestressed concrete stringer/multi-beam or girder carrying EB I-80 over 770th Street in Cass County, Iowa. It was built in 1958, so it is 67 years old, older 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 5 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 11,650 vehicles a day, roughly 41% of them trucks, projected to reach 11,650 by 2042. The structure is 162 ft (49.4 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesEB I-80
Crosses770th Street
Location1.7 Mi. E of Ia 148
RouteInterstate 80
CountyCass County
StateIowa
Coordinates41.4967, -94.72487
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment7: Better than present minimum criteria
Operating rating69.3 US tons
Inventory rating32.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length162 ft (49.4 m)
Longest span56 ft (17.1 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,650 (2022)
Projected traffic11,650 by 2042
Trucks41%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 EB I-80 over 770th Street built?

It was built in 1958, making it 67 years old in 2025.

What condition is EB I-80 over 770th Street 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 EB I-80 over 770th Street carry?

About 11,650 vehicles per day (2022 count), of which roughly 41% are trucks.

How long is EB I-80 over 770th Street?

The structure is 162 ft (49.4 m) long with a longest span of 56 ft (17.1 m) and a deck 36 ft wide.

Who owns EB I-80 over 770th Street?

It is owned by the State Highway Agency.