US Bridges

Gilbert ST over Ralston Creek

Poor

Johnson County, Iowa · 079061500 · Structure no. 000000000006450

Built
1972
53 years old
Condition
Poor
inspected July 2023
Type
Slab
Concrete Continuous
Length
83 ft
3 main spans
Daily traffic
14,025
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

Gilbert ST over Ralston Creek is a concrete continuous slab carrying Gilbert ST over Ralston Creek in Johnson County, Iowa. It was built in 1972, so it is 53 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 14,025 vehicles a day, projected to reach 14,025 by 2043. The structure is 83 ft (25.3 m) long and 61 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesGilbert ST
CrossesRalston Creek
Location079061500
RouteCity Street 0
CountyJohnson County
StateIowa
Coordinates41.65527, -91.53023
Functional classUrban Minor Arterial

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.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating55.6 US tons
Inventory rating33.3 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length83 ft (25.3 m)
Longest span31 ft (9.4 m)
Deck width61 ft (18.6 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,025 (2022)
Projected traffic14,025 by 2043
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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$85,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Gilbert ST over Ralston Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is Gilbert 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 July 2023.

How much traffic does Gilbert ST over Ralston Creek carry?

About 14,025 vehicles per day (2022 count).

How long is Gilbert ST over Ralston Creek?

The structure is 83 ft (25.3 m) long with a longest span of 31 ft (9.4 m) and a deck 61 ft wide.

Who owns Gilbert ST over Ralston Creek?

It is owned by the City or Municipal Highway Agency.