US Bridges

Il 99 over Missouri Creek

Fair

Schuyler County, Illinois · 1M N Brown County · Structure no. 085003000000000

Built
1986
39 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
200 ft
3 main spans
Daily traffic
375
2023 count
Owner
State
State Highway Agency

About this bridge

Il 99 over Missouri Creek is a prestressed concrete stringer/multi-beam or girder carrying Il 99 over Missouri Creek in Schuyler County, Illinois. It was built in 1986, so it is 39 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 6 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 375 vehicles a day, roughly 9% of them trucks, projected to reach 480 by 2046. The structure is 200 ft (61 m) long and 35 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

CarriesIl 99
CrossesMissouri Creek
Location1M N Brown County
RouteState Highway 99
Coordinates40.11983, -90.76727
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72.1 US tons
Inventory rating43.2 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length200 ft (61 m)
Longest span67 ft (20.4 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic375 (2023)
Projected traffic480 by 2046
Trucks9%
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 Il 99 over Missouri Creek built?

It was built in 1986, making it 39 years old in 2025.

What condition is Il 99 over Missouri 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 2024.

How much traffic does Il 99 over Missouri Creek carry?

About 375 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is Il 99 over Missouri Creek?

The structure is 200 ft (61 m) long with a longest span of 67 ft (20.4 m) and a deck 35 ft wide.

Who owns Il 99 over Missouri Creek?

It is owned by the State Highway Agency.