US Bridges

Route 593 over Clam Lake

Fair

Antrim County, Michigan · 0.5 MI S of Clam River · Structure no. 000000000000365

Built
1958
67 years old
Condition
Fair
inspected September 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
198 ft
5 main spans
Daily traffic
1,400
1997 count
Owner
County
County Highway Agency

About this bridge

Route 593 over Clam Lake is a prestressed concrete box beam or girders - multiple carrying Route 593 over Clam Lake in Antrim County, Michigan. It was built in 1958, so it is 67 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 1,400 vehicles a day, roughly 2% of them trucks, projected to reach 1,555 by 2018. The structure is 198 ft (60.3 m) long and 34 ft wide. If it were closed, the detour would be 34.8 mi (56 km).

Location

Open in Google Maps
CarriesRoute 593
CrossesClam Lake
Location0.5 MI S of Clam River
RouteCounty Highway 160
CountyAntrim County
StateMichigan
Coordinates44.94184, -85.28174
Functional classRural Major 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating80.4 US tons
Inventory rating48.2 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length198 ft (60.3 m)
Longest span50 ft (15.2 m)
Deck width34 ft (10.3 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,400 (1997)
Projected traffic1,555 by 2018
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 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 Route 593 over Clam Lake built?

It was built in 1958, making it 67 years old in 2025.

What condition is Route 593 over Clam Lake 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 2024.

How much traffic does Route 593 over Clam Lake carry?

About 1,400 vehicles per day (1997 count), of which roughly 2% are trucks.

How long is Route 593 over Clam Lake?

The structure is 198 ft (60.3 m) long with a longest span of 50 ft (15.2 m) and a deck 34 ft wide.

Who owns Route 593 over Clam Lake?

It is owned by the County Highway Agency.