US Bridges

Il 31 over RR - UP

Fair

McHenry County, Illinois · Ill 31 & US 14 Inter · Structure no. 056004000000000

Built
1971
54 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
191 ft
3 main spans
Daily traffic
34,400
2023 count
Owner
State
State Highway Agency

About this bridge

Il 31 over RR - UP is a steel continuous stringer/multi-beam or girder carrying Il 31 over RR - UP in McHenry County, Illinois. It was built in 1971, so it is 54 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 34,400 vehicles a day, roughly 6% of them trucks, projected to reach 41,160 by 2046. The structure is 191 ft (58.2 m) long and 87 ft wide.

Location

Open in Google Maps
CarriesIl 31
CrossesRR - UP
LocationIll 31 & US 14 Inter
RouteState Highway 31
CountyMcHenry County
StateIllinois
Coordinates42.22973, -88.28793
Functional classUrban Other Principal 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating62.8 US tons
Inventory rating37.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length191 ft (58.2 m)
Longest span67 ft (20.4 m)
Deck width87 ft (26.5 m)
Roadway width74 ft (22.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34,400 (2023)
Projected traffic41,160 by 2046
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed—
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.8 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was Il 31 over RR - UP built?

It was built in 1971, making it 54 years old in 2025.

What condition is Il 31 over RR - UP 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 August 2023.

How much traffic does Il 31 over RR - UP carry?

About 34,400 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is Il 31 over RR - UP?

The structure is 191 ft (58.2 m) long with a longest span of 67 ft (20.4 m) and a deck 87 ft wide.

Who owns Il 31 over RR - UP?

It is owned by the State Highway Agency.