US Bridges

US 61 NB over N Fork Maquoketa River

Fair

Jackson County, Iowa · 5.4 Mi. N of Jct. Ia 64 · Structure no. 000000000030170

Built
1967
58 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
365 ft
4 main spans
Daily traffic
4,050
2022 count
Owner
State
State Highway Agency

About this bridge

US 61 NB over N Fork Maquoketa River is a steel continuous stringer/multi-beam or girder carrying US 61 NB over N Fork Maquoketa River in Jackson County, Iowa. It was built in 1967, so it is 58 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 4,050 vehicles a day, roughly 22% of them trucks, projected to reach 4,050 by 2044. The structure is 365 ft (111.3 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesUS 61 NB
CrossesN Fork Maquoketa River
Location5.4 Mi. N of Jct. Ia 64
RouteU.S. Route 61
StateIowa
Coordinates42.14629, -90.67606
Functional classRural Principal Arterial - Other

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.7 US tons
Inventory rating35.9 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length365 ft (111.3 m)
Longest span101 ft (30.8 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,050 (2022)
Projected traffic4,050 by 2044
Trucks22%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 61 NB over N Fork Maquoketa River built?

It was built in 1967, making it 58 years old in 2025.

What condition is US 61 NB 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 July 2024.

How much traffic does US 61 NB over N Fork Maquoketa River carry?

About 4,050 vehicles per day (2022 count), of which roughly 22% are trucks.

How long is US 61 NB over N Fork Maquoketa River?

The structure is 365 ft (111.3 m) long with a longest span of 101 ft (30.8 m) and a deck 36 ft wide.

Who owns US 61 NB over N Fork Maquoketa River?

It is owned by the State Highway Agency.