US Bridges

Ill 29 over Mackinaw R Overflow

Fair

Tazewell County, Illinois · 2 MI N Greenvalley · Structure no. 090005200000000

Built
1921
104 years old, rebuilt 1960
Condition
Fair
inspected July 2023
Type
Slab
Concrete Continuous
Length
63 ft
2 main spans
Daily traffic
2,250
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 29 over Mackinaw R Overflow is a concrete continuous slab carrying Ill 29 over Mackinaw R Overflow in Tazewell County, Illinois. It was built in 1921 and reconstructed in 1960, so it is 104 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 2,250 vehicles a day, roughly 16% of them trucks, projected to reach 2,677 by 2046. The structure is 63 ft (19.2 m) long and 36 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesIll 29
CrossesMackinaw R Overflow
Location2 MI N Greenvalley
RouteState Highway 29
CountyTazewell County
StateIllinois
Coordinates40.43896, -89.65278
Functional classRural Minor Arterial

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55.7 US tons
Inventory rating34.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length63 ft (19.2 m)
Longest span30 ft (9.1 m)
Deck width36 ft (10.9 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,250 (2023)
Projected traffic2,677 by 2046
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Ill 29 over Mackinaw R Overflow built?

It was built in 1921, making it 104 years old in 2025. It was reconstructed in 1960.

What condition is Ill 29 over Mackinaw R Overflow 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 July 2023.

How much traffic does Ill 29 over Mackinaw R Overflow carry?

About 2,250 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is Ill 29 over Mackinaw R Overflow?

The structure is 63 ft (19.2 m) long with a longest span of 30 ft (9.1 m) and a deck 36 ft wide.

Who owns Ill 29 over Mackinaw R Overflow?

It is owned by the State Highway Agency.