US Bridges

79th ST over Flag Creek

Fair

Cook County, Illinois · 0.02 M E Wolf P10 · Structure no. 016309300000000

Built
1946
79 years old
Condition
Fair
inspected April 2023
Type
Frame
Concrete
Length
46 ft
1 main span
Daily traffic
6,300
2022 count
Owner
County
County Highway Agency

About this bridge

79th ST over Flag Creek is a concrete frame carrying 79th ST over Flag Creek in Cook County, Illinois. It was built in 1946, so it is 79 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 6,300 vehicles a day, roughly 3% of them trucks, projected to reach 5,202 by 2046. The structure is 46 ft (13.9 m) long and 53 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries79th ST
CrossesFlag Creek
Location0.02 M E Wolf P10
CountyCook County
StateIllinois
Coordinates41.74621, -87.89558
Functional classUrban Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
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 above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.4 US tons
Inventory rating24.7 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length46 ft (13.9 m)
Longest span46 ft (13.9 m)
Deck width53 ft (16.2 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,300 (2022)
Projected traffic5,202 by 2046
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 79th ST over Flag Creek built?

It was built in 1946, making it 79 years old in 2025.

What condition is 79th ST over Flag 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 79th ST over Flag Creek carry?

About 6,300 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is 79th ST over Flag Creek?

The structure is 46 ft (13.9 m) long with a longest span of 46 ft (13.9 m) and a deck 53 ft wide.

Who owns 79th ST over Flag Creek?

It is owned by the County Highway Agency.