US Bridges

Loc 400th ST over Maquoketa River

Good

Delaware County, Iowa · 090060501 · Structure no. 000000000142731

Built
1986
39 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
164 ft
3 main spans
Daily traffic
157
2022 count
Owner
County
County Highway Agency

About this bridge

Loc 400th ST over Maquoketa River is a prestressed concrete continuous stringer/multi-beam or girder carrying Loc 400th ST over Maquoketa River in Delaware County, Iowa. It was built in 1986, so it is 39 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 157 vehicles a day, projected to reach 157 by 2044. The structure is 164 ft (50 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesLoc 400th ST
CrossesMaquoketa River
Location090060501
RouteCounty Highway 0
CountyDelaware County
StateIowa
Coordinates42.64403, -91.5796
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating51.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length164 ft (50 m)
Longest span60 ft (18.3 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic157 (2022)
Projected traffic157 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Loc 400th ST over Maquoketa River built?

It was built in 1986, making it 39 years old in 2025.

What condition is Loc 400th ST over Maquoketa River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2024.

How much traffic does Loc 400th ST over Maquoketa River carry?

About 157 vehicles per day (2022 count).

How long is Loc 400th ST over Maquoketa River?

The structure is 164 ft (50 m) long with a longest span of 60 ft (18.3 m) and a deck 33 ft wide.

Who owns Loc 400th ST over Maquoketa River?

It is owned by the County Highway Agency.