US Bridges

County RD 100|SUNS over I-75 NB

Fair

Roscommon County, Michigan · 3.0 MI NW of M-18 · Structure no. 000000000009027

Built
1971
54 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
205 ft
3 main spans
Daily traffic
9,280
2012 count
Owner
State
State Highway Agency

About this bridge

County RD 100|SUNS over I-75 NB is a steel stringer/multi-beam or girder carrying County RD 100|SUNS over I-75 NB 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 9,280 vehicles a day, roughly 10% of them trucks, projected to reach 10,200 by 2032. The structure is 205 ft (62.4 m) long and 49 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCounty RD 100|SUNS
CrossesI-75 NB
Location3.0 MI NW of M-18
RouteCounty Highway 100
CountyRoscommon County
StateMichigan
Coordinates44.4936, -84.64569
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating78.9 US tons
Inventory rating47.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length205 ft (62.4 m)
Longest span115 ft (34.9 m)
Deck width49 ft (14.8 m)
Roadway width45 ft (13.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,280 (2012)
Projected traffic10,200 by 2032
Trucks10%
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 County RD 100|SUNS over I-75 NB built?

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

What condition is County RD 100|SUNS over I-75 NB 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 County RD 100|SUNS over I-75 NB carry?

About 9,280 vehicles per day (2012 count), of which roughly 10% are trucks.

How long is County RD 100|SUNS over I-75 NB?

The structure is 205 ft (62.4 m) long with a longest span of 115 ft (34.9 m) and a deck 49 ft wide.

Who owns County RD 100|SUNS over I-75 NB?

It is owned by the State Highway Agency.