US Bridges

100th ST over Drainage

Good

Montgomery County, Iowa · 073360505 · Structure no. 000000000256001

Built
2015
10 years old
Condition
Good
inspected June 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
93 ft
1 main span
Daily traffic
15
2022 count
Owner
County
County Highway Agency

About this bridge

100th ST over Drainage is a prestressed concrete stringer/multi-beam or girder carrying 100th ST over Drainage in Montgomery County, Iowa. It was built in 2015, so it is 10 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 15 vehicles a day, projected to reach 15 by 2043. The structure is 93 ft (28.3 m) long and 33 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries100th ST
CrossesDrainage
Location073360505
RouteCounty Highway 0
CountyMontgomery County
StateIowa
Coordinates41.15858, -95.00946
Functional classRural Minor Collector

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 protection8 Very GoodNo problems noted.
Last inspectionJune 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.1 US tons
Inventory rating55 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length93 ft (28.3 m)
Longest span90 ft (27.4 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15 (2022)
Projected traffic15 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 100th ST over Drainage built?

It was built in 2015, making it 10 years old in 2025.

What condition is 100th ST over Drainage 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 June 2022.

How much traffic does 100th ST over Drainage carry?

About 15 vehicles per day (2022 count).

How long is 100th ST over Drainage?

The structure is 93 ft (28.3 m) long with a longest span of 90 ft (27.4 m) and a deck 33 ft wide.

Who owns 100th ST over Drainage?

It is owned by the County Highway Agency.