US Bridges

W 4th ST over US 20

Fair

Black Hawk County, Iowa · 0.5 Mi. E of Jct. US 63 · Structure no. 000000000605205

Built
1984
41 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
295 ft
4 main spans
Daily traffic
2,670
2022 count
Owner
State
State Highway Agency

About this bridge

W 4th ST over US 20 is a prestressed concrete stringer/multi-beam or girder carrying W 4th ST over US 20 in Black Hawk County, Iowa. It was built in 1984, so it is 41 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 2,670 vehicles a day, projected to reach 2,670 by 2043. The structure is 295 ft (89.9 m) long and 47 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesW 4th ST
CrossesUS 20
Location0.5 Mi. E of Jct. US 63
RouteCity Street 0
CountyBlack Hawk County
StateIowa
Coordinates42.45537, -92.39589
Functional classUrban Minor 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating99.8 US tons
Inventory rating46.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length295 ft (89.9 m)
Longest span97 ft (29.6 m)
Deck width47 ft (14.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,670 (2022)
Projected traffic2,670 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

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 W 4th ST over US 20 built?

It was built in 1984, making it 41 years old in 2025.

What condition is W 4th ST over US 20 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 August 2023.

How much traffic does W 4th ST over US 20 carry?

About 2,670 vehicles per day (2022 count).

How long is W 4th ST over US 20?

The structure is 295 ft (89.9 m) long with a longest span of 97 ft (29.6 m) and a deck 47 ft wide.

Who owns W 4th ST over US 20?

It is owned by the State Highway Agency.