US Bridges

US-31 SB over ST Joseph River

Fair

Berrien County, Michigan · 2.0 MI W of Niles · Structure no. 000000000000889

Built
1984
41 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
1,310 ft
5 main spans
Daily traffic
7,675
2015 count
Owner
State
State Highway Agency

About this bridge

US-31 SB over ST Joseph River is a steel continuous stringer/multi-beam or girder carrying US-31 SB over ST Joseph River in Berrien County, Michigan. It was built in 1984, so it is 41 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 7,675 vehicles a day, roughly 15% of them trucks, projected to reach 8,826 by 2035. The structure is 1,310 ft (399.3 m) long and 48 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesUS-31 SB
CrossesST Joseph River
Location2.0 MI W of Niles
RouteU.S. Route 31
Coordinates41.83668, -86.31418
Functional classRural Principal Arterial - Other

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68.6 US tons
Inventory rating41.1 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 25 or greater
Structure length1,310 ft (399.3 m)
Longest span298 ft (90.8 m)
Deck width48 ft (14.6 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,675 (2015)
Projected traffic8,826 by 2035
Trucks15%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was US-31 SB over ST Joseph River built?

It was built in 1984, making it 41 years old in 2025.

What condition is US-31 SB over ST Joseph 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 May 2024.

How much traffic does US-31 SB over ST Joseph River carry?

About 7,675 vehicles per day (2015 count), of which roughly 15% are trucks.

How long is US-31 SB over ST Joseph River?

The structure is 1,310 ft (399.3 m) long with a longest span of 298 ft (90.8 m) and a deck 48 ft wide.

Who owns US-31 SB over ST Joseph River?

It is owned by the State Highway Agency.