US Bridges

Ill 29 over Mackinaw River

Fair

Tazewell County, Illinois · N of Green Valley · Structure no. 090014300000000

Built
1997
28 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
880 ft
6 main spans
Daily traffic
2,250
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 29 over Mackinaw River is a steel continuous stringer/multi-beam or girder carrying Ill 29 over Mackinaw River in Tazewell County, Illinois. It was built in 1997, so it is 28 years old, younger 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 880 ft (268.2 m) long and 35 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesIll 29
CrossesMackinaw River
LocationN of Green Valley
RouteState Highway 29
CountyTazewell County
StateIllinois
Coordinates40.44643, -89.65313
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to 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 alignment6: Equal to present minimum criteria
Operating rating77.2 US tons
Inventory rating46.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length880 ft (268.2 m)
Longest span155 ft (47.2 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 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 River built?

It was built in 1997, making it 28 years old in 2025.

What condition is Ill 29 over Mackinaw River 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 November 2023.

How much traffic does Ill 29 over Mackinaw River carry?

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

How long is Ill 29 over Mackinaw River?

The structure is 880 ft (268.2 m) long with a longest span of 155 ft (47.2 m) and a deck 35 ft wide.

Who owns Ill 29 over Mackinaw River?

It is owned by the State Highway Agency.