US Bridges

SB Dubuque ST over I 80

Fair

Johnson County, Iowa · At the Jct. of S.R. W66 · Structure no. 000000000032110

Built
1963
62 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
240 ft
4 main spans
Daily traffic
2,750
2022 count
Owner
State
State Highway Agency

About this bridge

SB Dubuque ST over I 80 is a steel continuous stringer/multi-beam or girder carrying SB Dubuque ST over I 80 in Johnson County, Iowa. It was built in 1963, so it is 62 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 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 2,750 vehicles a day, projected to reach 2,750 by 2044. The structure is 240 ft (73.2 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSB Dubuque ST
CrossesI 80
LocationAt the Jct. of S.R. W66
RouteCity Street 0
CountyJohnson County
StateIowa
Coordinates41.68701, -91.54032
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
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 rating50 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length240 ft (73.2 m)
Longest span66 ft (20.1 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,750 (2022)
Projected traffic2,750 by 2044
Trucks0%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.2 mi (2 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 SB Dubuque ST over I 80 built?

It was built in 1963, making it 62 years old in 2025.

What condition is SB Dubuque ST over I 80 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 September 2024.

How much traffic does SB Dubuque ST over I 80 carry?

About 2,750 vehicles per day (2022 count).

How long is SB Dubuque ST over I 80?

The structure is 240 ft (73.2 m) long with a longest span of 66 ft (20.1 m) and a deck 36 ft wide.

Who owns SB Dubuque ST over I 80?

It is owned by the State Highway Agency.