US Bridges

Johnson ST over Ralston Creek

Poor

Johnson County, Iowa · 079061000 · Structure no. 000000000006460

Built
1930
95 years old
Condition
Poor
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
32 ft
1 main span
Daily traffic
2,356
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

Johnson ST over Ralston Creek is a steel stringer/multi-beam or girder carrying Johnson ST over Ralston Creek in Johnson County, Iowa. It was built in 1930, so it is 95 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 2,356 vehicles a day, projected to reach 2,356 by 2043. The structure is 32 ft (9.8 m) long and 34 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesJohnson ST
CrossesRalston Creek
Location079061000
RouteCity Street 0
CountyJohnson County
StateIowa
Coordinates41.66071, -91.52721
Functional classUrban Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating47.6 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length32 ft (9.8 m)
Longest span30 ft (9.1 m)
Deck width34 ft (10.5 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,356 (2022)
Projected traffic2,356 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$33,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Johnson ST over Ralston Creek built?

It was built in 1930, making it 95 years old in 2025.

What condition is Johnson ST over Ralston Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2023.

How much traffic does Johnson ST over Ralston Creek carry?

About 2,356 vehicles per day (2022 count).

How long is Johnson ST over Ralston Creek?

The structure is 32 ft (9.8 m) long with a longest span of 30 ft (9.1 m) and a deck 34 ft wide.

Who owns Johnson ST over Ralston Creek?

It is owned by the City or Municipal Highway Agency.