WB US 20 over N Fork Maquoketa River
FairDubuque County, Iowa · 0.6 Mi. W of Jct. Ia 136 · Structure no. 000000000023780
- Built
- 1958
- 67 years old
- Condition
- Fair
- inspected August 2023
- Type
- Box Beam or Girders - Single or Spread
- Concrete Continuous
- Length
- 502 ft
- 5 main spans
- Daily traffic
- 5,450
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
WB US 20 over N Fork Maquoketa River is a concrete continuous box beam or girders - single or spread carrying WB US 20 over N Fork Maquoketa River in Dubuque 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 5,450 vehicles a day, roughly 19% of them trucks, projected to reach 5,450 by 2043. The structure is 502 ft (153 m) long and 33 ft wide.
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was WB US 20 over N Fork Maquoketa River built?
It was built in 1958, making it 67 years old in 2025.
What condition is WB US 20 over N Fork Maquoketa River 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 WB US 20 over N Fork Maquoketa River carry?
About 5,450 vehicles per day (2022 count), of which roughly 19% are trucks.
How long is WB US 20 over N Fork Maquoketa River?
The structure is 502 ft (153 m) long with a longest span of 109 ft (33.2 m) and a deck 33 ft wide.
Who owns WB US 20 over N Fork Maquoketa River?
It is owned by the State Highway Agency.