US Bridges

I-94 Bl over Black River

Fair

St. Clair County, Michigan · In Port Huron (military a · Structure no. 000000000009956

Built
1991
34 years old
Condition
Fair
inspected April 2024
Type
Movable - Bascule
Steel
Length
147 ft
1 main span
Daily traffic
9,408
2021 count
Owner
State
State Highway Agency

About this bridge

I-94 Bl over Black River is a steel movable - bascule carrying I-94 Bl over Black River in St. Clair County, Michigan. It was built in 1991, so it is 34 years old, younger 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 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 9,408 vehicles a day, roughly 3% of them trucks, projected to reach 9,706 by 2025. The structure is 147 ft (44.8 m) long and 67 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesI-94 Bl
CrossesBlack River
LocationIn Port Huron (military a
RouteInterstate 94
CountySt. Clair County
StateMichigan
Coordinates42.97576, -82.42429
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment7: Better than present minimum criteria
Operating rating54.7 US tons
Inventory rating32.8 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckOpen grating
Main spans1 (+2 approach)
Design loadHS 25 or greater
Structure length147 ft (44.8 m)
Longest span100 ft (30.5 m)
Deck width67 ft (20.4 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,408 (2021)
Projected traffic9,706 by 2025
Trucks3%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
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 proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was I-94 Bl over Black River built?

It was built in 1991, making it 34 years old in 2025.

What condition is I-94 Bl over Black River 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 April 2024.

How much traffic does I-94 Bl over Black River carry?

About 9,408 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is I-94 Bl over Black River?

The structure is 147 ft (44.8 m) long with a longest span of 100 ft (30.5 m) and a deck 67 ft wide.

Who owns I-94 Bl over Black River?

It is owned by the State Highway Agency.