US Bridges

Somonauk RD.(FAS96 over Somonauk Creek

Good

DeKalb County, Illinois · 500N. 1540E. · Structure no. 019307600000000

Built
2017
8 years old
Condition
Good
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
85 ft
1 main span
Daily traffic
3,200
2021 count
Owner
County
County Highway Agency

About this bridge

Somonauk RD.(FAS96 over Somonauk Creek is a steel stringer/multi-beam or girder carrying Somonauk RD.(FAS96 over Somonauk Creek in DeKalb County, Illinois. It was built in 2017, so it is 8 years old, younger than the Illinois average of 45.3 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 3,200 vehicles a day, roughly 14% of them trucks, projected to reach 3,584 by 2046. The structure is 85 ft (26 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesSomonauk RD.(FAS96
CrossesSomonauk Creek
Location500N. 1540E.
RouteCounty Highway 0
CountyDeKalb County
StateIllinois
Coordinates41.70482, -88.65235
Functional classRural Major 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 inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum 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 rating44.3 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length85 ft (26 m)
Longest span82 ft (25 m)
Deck width30 ft (9.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2021)
Projected traffic3,584 by 2046
Trucks14%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Somonauk RD.(FAS96 over Somonauk Creek built?

It was built in 2017, making it 8 years old in 2025.

What condition is Somonauk RD.(FAS96 over Somonauk 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 October 2023.

How much traffic does Somonauk RD.(FAS96 over Somonauk Creek carry?

About 3,200 vehicles per day (2021 count), of which roughly 14% are trucks.

How long is Somonauk RD.(FAS96 over Somonauk Creek?

The structure is 85 ft (26 m) long with a longest span of 82 ft (25 m) and a deck 30 ft wide.

Who owns Somonauk RD.(FAS96 over Somonauk Creek?

It is owned by the County Highway Agency.