US Bridges

Suydam RD over Buck Br Somonauk Crk

Good

DeKalb County, Illinois · 200N 1395E · Structure no. 019306400000000

Built
2015
10 years old
Condition
Good
inspected October 2021
Type
Stringer/Multi-beam or Girder
Steel
Length
40 ft
1 main span
Daily traffic
900
2024 count
Owner
County
County Highway Agency

About this bridge

Suydam RD over Buck Br Somonauk Crk is a steel stringer/multi-beam or girder carrying Suydam RD over Buck Br Somonauk Crk in DeKalb County, Illinois. It was built in 2015, so it is 10 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 900 vehicles a day, roughly 8% of them trucks, projected to reach 868 by 2046. The structure is 40 ft (12.3 m) long and 32 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesSuydam RD
CrossesBuck Br Somonauk Crk
Location200N 1395E
RouteCounty Highway 0
CountyDeKalb County
StateIllinois
Coordinates41.6599, -88.68114
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 protection7 GoodSome minor problems.
Last inspectionOctober 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length40 ft (12.3 m)
Longest span37 ft (11.2 m)
Deck width32 ft (9.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic900 (2024)
Projected traffic868 by 2046
Trucks8%
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 Suydam RD over Buck Br Somonauk Crk built?

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

What condition is Suydam RD over Buck Br Somonauk Crk 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 2021.

How much traffic does Suydam RD over Buck Br Somonauk Crk carry?

About 900 vehicles per day (2024 count), of which roughly 8% are trucks.

How long is Suydam RD over Buck Br Somonauk Crk?

The structure is 40 ft (12.3 m) long with a longest span of 37 ft (11.2 m) and a deck 32 ft wide.

Who owns Suydam RD over Buck Br Somonauk Crk?

It is owned by the County Highway Agency.