US Bridges

SEIBERLINGST(MS170 over Mosquito Creek

Fair

Macon County, Illinois · E Edge of Blue Mound · Structure no. 058601900000000

Built
1982
43 years old
Condition
Fair
inspected December 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
30 ft
1 main span
Daily traffic
575
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

SEIBERLINGST(MS170 over Mosquito Creek is a prestressed concrete box beam or girders - multiple carrying SEIBERLINGST(MS170 over Mosquito Creek in Macon County, Illinois. It was built in 1982, so it is 43 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 575 vehicles a day, roughly 6% of them trucks, projected to reach 581 by 2046. The structure is 30 ft (9.1 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSEIBERLINGST(MS170
CrossesMosquito Creek
LocationE Edge of Blue Mound
RouteCity Street 0
CountyMacon County
StateIllinois
Coordinates39.69921, -89.11439
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 inspectionDecember 2023
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 adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.9 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 length30 ft (9.1 m)
Longest span28 ft (8.4 m)
Deck width28 ft (8.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic575 (2020)
Projected traffic581 by 2046
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 SEIBERLINGST(MS170 over Mosquito Creek built?

It was built in 1982, making it 43 years old in 2025.

What condition is SEIBERLINGST(MS170 over Mosquito 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 December 2023.

How much traffic does SEIBERLINGST(MS170 over Mosquito Creek carry?

About 575 vehicles per day (2020 count), of which roughly 6% are trucks.

How long is SEIBERLINGST(MS170 over Mosquito Creek?

The structure is 30 ft (9.1 m) long with a longest span of 28 ft (8.4 m) and a deck 28 ft wide.

Who owns SEIBERLINGST(MS170 over Mosquito Creek?

It is owned by the City or Municipal Highway Agency.