Il 31 & 120 over Boone Creek
GoodMcHenry County, Illinois · 1.6M W of Chapel Hil · Structure no. 056006000000000
- Built
- 1990
- 35 years old, rebuilt 2014
- Condition
- Good
- inspected June 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 95 ft
- 1 main span
- Daily traffic
- 30,300
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Il 31 & 120 over Boone Creek is a prestressed concrete stringer/multi-beam or girder carrying Il 31 & 120 over Boone Creek in McHenry County, Illinois. It was built in 1990 and reconstructed in 2014, so it is 35 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 30,300 vehicles a day, roughly 5% of them trucks, projected to reach 37,800 by 2046. The structure is 95 ft (28.9 m) long and 87 ft wide. If it were closed, the detour would be 3.1 mi (5 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Il 31 & 120 over Boone Creek built?
It was built in 1990, making it 35 years old in 2025. It was reconstructed in 2014.
What condition is Il 31 & 120 over Boone Creek 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 June 2024.
How much traffic does Il 31 & 120 over Boone Creek carry?
About 30,300 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is Il 31 & 120 over Boone Creek?
The structure is 95 ft (28.9 m) long with a longest span of 93 ft (28.2 m) and a deck 87 ft wide.
Who owns Il 31 & 120 over Boone Creek?
It is owned by the State Highway Agency.