US Bridges

Au Sable RD(CR602) over S Br Au Sable River

Fair

Roscommon County, Michigan · Au Sable Twp Sec 21 · Structure no. 000000000013141

Built
1976
49 years old
Condition
Fair
inspected June 2024
Type
Culvert
Steel
Length
27 ft
2 main spans
Daily traffic
200
2002 count
Owner
County
County Highway Agency

About this bridge

Au Sable RD(CR602) over S Br Au Sable River is a steel culvert carrying Au Sable RD(CR602) over S Br Au Sable River in Roscommon County, Michigan. It was built in 1976, so it is 49 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 200 vehicles a day, roughly 6% of them trucks, projected to reach 300 by 2022. The structure is 27 ft (8.1 m) long. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesAu Sable RD(CR602)
CrossesS Br Au Sable River
LocationAu Sable Twp Sec 21
RouteCounty Highway 602
CountyRoscommon County
StateMichigan
Coordinates44.45862, -84.44384
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating107.1 US tons
Inventory rating64.3 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadHS 20
Structure length27 ft (8.1 m)
Longest span11 ft (3.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic200 (2002)
Projected traffic300 by 2022
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Au Sable RD(CR602) over S Br Au Sable River built?

It was built in 1976, making it 49 years old in 2025.

What condition is Au Sable RD(CR602) over S Br Au Sable 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 June 2024.

How much traffic does Au Sable RD(CR602) over S Br Au Sable River carry?

About 200 vehicles per day (2002 count), of which roughly 6% are trucks.

How long is Au Sable RD(CR602) over S Br Au Sable River?

The structure is 27 ft (8.1 m) long with a longest span of 11 ft (3.4 m).

Who owns Au Sable RD(CR602) over S Br Au Sable River?

It is owned by the County Highway Agency.