US Bridges

E23 170th ST over Keigley Branch

Good

Story County, Iowa · 084230701 · Structure no. 000000000315272

Built
2013
12 years old
Condition
Good
inspected December 2022
Type
Slab
Concrete Continuous
Length
121 ft
3 main spans
Daily traffic
120
2022 count
Owner
County
County Highway Agency

About this bridge

E23 170th ST over Keigley Branch is a concrete continuous slab carrying E23 170th ST over Keigley Branch in Story County, Iowa. It was built in 2013, so it is 12 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 120 vehicles a day, projected to reach 120 by 2043. The structure is 121 ft (36.9 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesE23 170th ST
CrossesKeigley Branch
Location084230701
RouteCounty Highway 0
CountyStory County
StateIowa
Coordinates42.1066, -93.5752
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating77.7 US tons
Inventory rating46.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length121 ft (36.9 m)
Longest span47 ft (14.3 m)
Deck width33 ft (10.1 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic120 (2022)
Projected traffic120 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 E23 170th ST over Keigley Branch built?

It was built in 2013, making it 12 years old in 2025.

What condition is E23 170th ST over Keigley Branch 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 December 2022.

How much traffic does E23 170th ST over Keigley Branch carry?

About 120 vehicles per day (2022 count).

How long is E23 170th ST over Keigley Branch?

The structure is 121 ft (36.9 m) long with a longest span of 47 ft (14.3 m) and a deck 33 ft wide.

Who owns E23 170th ST over Keigley Branch?

It is owned by the County Highway Agency.