I-75 Intl Bridge over ST Mary Riv/Portage Av W
FairPosted for loadChippewa County, Michigan · In Sault Ste Marie · Structure no. 000000000001582
- Built
- 1962
- 63 years old
- Condition
- Fair
- inspected August 2023
- Type
- Truss - Thru
- Steel Continuous
- Length
- 9,280 ft
- 8 main spans
- Daily traffic
- 5,242
- 2007 count
- Owner
- Toll Authority
- State Toll Authority
About this bridge
I-75 Intl Bridge over ST Mary Riv/Portage Av W is a steel continuous truss - thru carrying I-75 Intl Bridge over ST Mary Riv/Portage Av W in Chippewa County, Michigan. It was built in 1962, so it is 63 years old, older than the Michigan average of 48.3 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.
It carries about 5,242 vehicles a day, roughly 9% of them trucks, projected to reach 5,701 by 2018. The structure is 9,280 ft (2,828.6 m) long and 34 ft wide. If it were closed, the detour would be 124.3 mi (200 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I-75 Intl Bridge over ST Mary Riv/Portage Av W built?
It was built in 1962, making it 63 years old in 2025.
What condition is I-75 Intl Bridge over ST Mary Riv/Portage Av W 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 I-75 Intl Bridge over ST Mary Riv/Portage Av W carry?
About 5,242 vehicles per day (2007 count), of which roughly 9% are trucks.
How long is I-75 Intl Bridge over ST Mary Riv/Portage Av W?
The structure is 9,280 ft (2,828.6 m) long with a longest span of 430 ft (131.1 m) and a deck 34 ft wide.
Who owns I-75 Intl Bridge over ST Mary Riv/Portage Av W?
It is owned by the State Toll Authority.