NB I-155 over Mackinaw River
PoorTazewell County, Illinois · 1MI N JCT I-155 /122 · Structure no. 090010000000000
- Built
- 1970
- 55 years old
- Condition
- Poor
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 550 ft
- 6 main spans
- Daily traffic
- 6,900
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
NB I-155 over Mackinaw River is a steel continuous stringer/multi-beam or girder carrying NB I-155 over Mackinaw River in Tazewell County, Illinois. It was built in 1970, so it is 55 years old, older than the Illinois average of 45.3 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 6,900 vehicles a day, roughly 17% of them trucks, projected to reach 6,464 by 2046. The structure is 550 ft (167.6 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 3 Serious | Loss of section, deterioration, spalling or scour have seriously affected primary structural components. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was NB I-155 over Mackinaw River built?
It was built in 1970, making it 55 years old in 2025.
What condition is NB I-155 over Mackinaw River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in March 2024.
How much traffic does NB I-155 over Mackinaw River carry?
About 6,900 vehicles per day (2023 count), of which roughly 17% are trucks.
How long is NB I-155 over Mackinaw River?
The structure is 550 ft (167.6 m) long with a longest span of 140 ft (42.7 m) and a deck 42 ft wide.
Who owns NB I-155 over Mackinaw River?
It is owned by the State Highway Agency.