US Bridges

Knox RD over I-96

Fair

Ionia County, Michigan · 0.3 MI W of Portland · Structure no. 000000000003991

Built
1959
66 years old
Condition
Fair
inspected November 2024
Type
Tee Beam
Concrete Continuous
Length
250 ft
4 main spans
Daily traffic
530
1974 count
Owner
State
State Highway Agency

About this bridge

Knox RD over I-96 is a concrete continuous tee beam carrying Knox RD over I-96 in Ionia County, Michigan. It was built in 1959, so it is 66 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 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 530 vehicles a day, projected to reach 530 by 1977. The structure is 250 ft (76.2 m) long and 33 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesKnox RD
CrossesI-96
Location0.3 MI W of Portland
RouteCounty Highway 0
CountyIonia County
StateMichigan
Coordinates42.86198, -84.92223
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.3 US tons
Inventory rating24.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length250 ft (76.2 m)
Longest span71 ft (21.6 m)
Deck width33 ft (10.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic530 (1974)
Projected traffic530 by 1977
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Knox RD over I-96 built?

It was built in 1959, making it 66 years old in 2025.

What condition is Knox RD over I-96 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 November 2024.

How much traffic does Knox RD over I-96 carry?

About 530 vehicles per day (1974 count).

How long is Knox RD over I-96?

The structure is 250 ft (76.2 m) long with a longest span of 71 ft (21.6 m) and a deck 33 ft wide.

Who owns Knox RD over I-96?

It is owned by the State Highway Agency.