US Bridges

I-75 NB|M-55 WB over Old 76|S Saint Helen RD

Fair

Roscommon County, Michigan · 9 MI W of West Branch · Structure no. 000000000009019

Built
1971
54 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
162 ft
3 main spans
Daily traffic
7,368
2020 count
Owner
State
State Highway Agency

About this bridge

I-75 NB|M-55 WB over Old 76|S Saint Helen RD is a steel stringer/multi-beam or girder carrying I-75 NB|M-55 WB over Old 76|S Saint Helen RD in Roscommon County, Michigan. It was built in 1971, so it is 54 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.

It carries about 7,368 vehicles a day, roughly 10% of them trucks, projected to reach 8,473 by 2040. The structure is 162 ft (49.4 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI-75 NB|M-55 WB
CrossesOld 76|S Saint Helen RD
Location9 MI W of West Branch
RouteInterstate 75
Coordinates44.31185, -84.40981
Functional classRural Principal Arterial - Interstate

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating91.8 US tons
Inventory rating55 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length162 ft (49.4 m)
Longest span93 ft (28.3 m)
Deck width44 ft (13.5 m)
Roadway width40 ft (12.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,368 (2020)
Projected traffic8,473 by 2040
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-75 NB|M-55 WB over Old 76|S Saint Helen RD built?

It was built in 1971, making it 54 years old in 2025.

What condition is I-75 NB|M-55 WB over Old 76|S Saint Helen RD 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 September 2023.

How much traffic does I-75 NB|M-55 WB over Old 76|S Saint Helen RD carry?

About 7,368 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is I-75 NB|M-55 WB over Old 76|S Saint Helen RD?

The structure is 162 ft (49.4 m) long with a longest span of 93 ft (28.3 m) and a deck 44 ft wide.

Who owns I-75 NB|M-55 WB over Old 76|S Saint Helen RD?

It is owned by the State Highway Agency.