US Bridges

TR 321 over Mdl Fk Shoal CR

Fair

Montgomery County, Illinois · 4 MI SW Hillsboro · Structure no. 068324700000000

Built
1978
47 years old
Condition
Fair
inspected January 2025
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
70 ft
3 main spans
Daily traffic
75
2020 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

TR 321 over Mdl Fk Shoal CR is a prestressed concrete box beam or girders - multiple carrying TR 321 over Mdl Fk Shoal CR in Montgomery County, Illinois. It was built in 1978, so it is 47 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 75 vehicles a day, roughly 3% of them trucks, projected to reach 76 by 2046. The structure is 70 ft (21.3 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesTR 321
CrossesMdl Fk Shoal CR
Location4 MI SW Hillsboro
RouteCounty Highway 0
CountyMontgomery County
StateIllinois
Coordinates39.10804, -89.52095
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating57.5 US tons
Inventory rating34.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length70 ft (21.3 m)
Longest span21 ft (6.4 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic75 (2020)
Projected traffic76 by 2046
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerTown or Township Highway Agency
Maintained byTown or Township 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 TR 321 over Mdl Fk Shoal CR built?

It was built in 1978, making it 47 years old in 2025.

What condition is TR 321 over Mdl Fk Shoal CR 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 January 2025.

How much traffic does TR 321 over Mdl Fk Shoal CR carry?

About 75 vehicles per day (2020 count), of which roughly 3% are trucks.

How long is TR 321 over Mdl Fk Shoal CR?

The structure is 70 ft (21.3 m) long with a longest span of 21 ft (6.4 m) and a deck 22 ft wide.

Who owns TR 321 over Mdl Fk Shoal CR?

It is owned by the Town or Township Highway Agency.