US Bridges

TR 438A over Blackston Branch

Good

Iroquois County, Illinois · 3.25 MI NE of Iroq. · Structure no. 038375100000000

Built
2003
22 years old
Condition
Good
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
64 ft
1 main span
Daily traffic
25
2022 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

TR 438A over Blackston Branch is a prestressed concrete box beam or girders - multiple carrying TR 438A over Blackston Branch in Iroquois County, Illinois. It was built in 2003, so it is 22 years old, younger than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 25 vehicles a day, projected to reach 25 by 2046. The structure is 64 ft (19.5 m) long and 30 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesTR 438A
CrossesBlackston Branch
Location3.25 MI NE of Iroq.
RouteCounty Highway 0
CountyIroquois County
StateIllinois
Coordinates40.85612, -87.55864
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length64 ft (19.5 m)
Longest span61 ft (18.5 m)
Deck width30 ft (9.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25 (2022)
Projected traffic25 by 2046
Trucks0%
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 438A over Blackston Branch built?

It was built in 2003, making it 22 years old in 2025.

What condition is TR 438A over Blackston Branch in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2023.

How much traffic does TR 438A over Blackston Branch carry?

About 25 vehicles per day (2022 count).

How long is TR 438A over Blackston Branch?

The structure is 64 ft (19.5 m) long with a longest span of 61 ft (18.5 m) and a deck 30 ft wide.

Who owns TR 438A over Blackston Branch?

It is owned by the Town or Township Highway Agency.