US Bridges

Shabbona Grove Roa over Somonauk Creek

Fair

DeKalb County, Illinois · 700N 1270E · Structure no. 019542200000000

Built
1978
47 years old
Condition
Fair
inspected April 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
114 ft
3 main spans
Daily traffic
50
2021 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

Shabbona Grove Roa over Somonauk Creek is a prestressed concrete box beam or girders - multiple carrying Shabbona Grove Roa over Somonauk Creek in DeKalb County, Illinois. It was built in 1978, so it is 47 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 50 vehicles a day, projected to reach 56 by 2046. The structure is 114 ft (34.7 m) long and 28 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesShabbona Grove Roa
CrossesSomonauk Creek
Location700N 1270E
RouteCounty Highway 0
CountyDeKalb County
StateIllinois
Coordinates41.73324, -88.70123
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.9 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length114 ft (34.7 m)
Longest span38 ft (11.6 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2021)
Projected traffic56 by 2046
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerTown or Township Highway Agency
Maintained byTown or Township 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 Shabbona Grove Roa over Somonauk Creek built?

It was built in 1978, making it 47 years old in 2025.

What condition is Shabbona Grove Roa over Somonauk Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.

How much traffic does Shabbona Grove Roa over Somonauk Creek carry?

About 50 vehicles per day (2021 count).

How long is Shabbona Grove Roa over Somonauk Creek?

The structure is 114 ft (34.7 m) long with a longest span of 38 ft (11.6 m) and a deck 28 ft wide.

Who owns Shabbona Grove Roa over Somonauk Creek?

It is owned by the Town or Township Highway Agency.