US Bridges

Ia 1 NB over Ralston Creek

Good

Johnson County, Iowa · 2.3 Mi. S. of I-80 · Structure no. 000000000031762

Built
2019
6 years old
Condition
Good
inspected May 2024
Type
Slab
Concrete Continuous
Length
45 ft
1 main span
Daily traffic
2,850
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 1 NB over Ralston Creek is a concrete continuous slab carrying Ia 1 NB over Ralston Creek in Johnson County, Iowa. It was built in 2019, so it is 6 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 2,850 vehicles a day, roughly 3% of them trucks, projected to reach 2,850 by 2044. The structure is 45 ft (13.7 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIa 1 NB
CrossesRalston Creek
Location2.3 Mi. S. of I-80
RouteState Highway 1
CountyJohnson County
StateIowa
Coordinates41.66161, -91.52282
Functional classUrban Other Principal Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length45 ft (13.7 m)
Longest span42 ft (12.8 m)
Deck width44 ft (13.5 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,850 (2022)
Projected traffic2,850 by 2044
Trucks3%
Lanes on structure2
Traffic directionTwo-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 Ia 1 NB over Ralston Creek built?

It was built in 2019, making it 6 years old in 2025.

What condition is Ia 1 NB over Ralston Creek 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 May 2024.

How much traffic does Ia 1 NB over Ralston Creek carry?

About 2,850 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is Ia 1 NB over Ralston Creek?

The structure is 45 ft (13.7 m) long with a longest span of 42 ft (12.8 m) and a deck 44 ft wide.

Who owns Ia 1 NB over Ralston Creek?

It is owned by the State Highway Agency.