US Bridges

WB Coll Ia 100 over I-380

Fair

Linn County, Iowa · 0.1 Mi. N of Jct. 100 · Structure no. 000000000604720

Built
1982
43 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
268 ft
4 main spans
Daily traffic
10,700
2022 count
Owner
State
State Highway Agency

About this bridge

WB Coll Ia 100 over I-380 is a prestressed concrete stringer/multi-beam or girder carrying WB Coll Ia 100 over I-380 in Linn County, Iowa. It was built in 1982, so it is 43 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 10,700 vehicles a day, roughly 3% of them trucks, projected to reach 10,700 by 2044. The structure is 268 ft (81.7 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesWB Coll Ia 100
CrossesI-380
Location0.1 Mi. N of Jct. 100
RouteState Highway 100
StateIowa
Coordinates42.02862, -91.67284
Functional classUrban Other Principal Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating99.8 US tons
Inventory rating40.3 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length268 ft (81.7 m)
Longest span97 ft (29.6 m)
Deck width45 ft (13.8 m)
Roadway width42 ft (12.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,700 (2022)
Projected traffic10,700 by 2044
Trucks3%
Lanes on structure3
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 WB Coll Ia 100 over I-380 built?

It was built in 1982, making it 43 years old in 2025.

What condition is WB Coll Ia 100 over I-380 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 October 2024.

How much traffic does WB Coll Ia 100 over I-380 carry?

About 10,700 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is WB Coll Ia 100 over I-380?

The structure is 268 ft (81.7 m) long with a longest span of 97 ft (29.6 m) and a deck 45 ft wide.

Who owns WB Coll Ia 100 over I-380?

It is owned by the State Highway Agency.