US Bridges

CO Road 643 over Paint River

Fair

Iron County, Michigan · Sec 36 T44N R34W Iron CO · Structure no. 000000000004196

Built
1959
66 years old, rebuilt 2015
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
180 ft
3 main spans
Daily traffic
630
2015 count
Owner
County
County Highway Agency

About this bridge

CO Road 643 over Paint River is a steel stringer/multi-beam or girder carrying CO Road 643 over Paint River in Iron County, Michigan. It was built in 1959 and reconstructed in 2015, 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 630 vehicles a day, roughly 3% of them trucks, projected to reach 700 by 2035. The structure is 180 ft (54.9 m) long and 30 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCO Road 643
CrossesPaint River
LocationSec 36 T44N R34W Iron CO
RouteCounty Highway 3649
CountyIron County
StateMichigan
Coordinates46.16914, -88.50427
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating96.8 US tons
Inventory rating74.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length180 ft (54.9 m)
Longest span59 ft (18 m)
Deck width30 ft (9.1 m)
Roadway width27 ft (8.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic630 (2015)
Projected traffic700 by 2035
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 CO Road 643 over Paint River built?

It was built in 1959, making it 66 years old in 2025. It was reconstructed in 2015.

What condition is CO Road 643 over Paint 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 September 2024.

How much traffic does CO Road 643 over Paint River carry?

About 630 vehicles per day (2015 count), of which roughly 3% are trucks.

How long is CO Road 643 over Paint River?

The structure is 180 ft (54.9 m) long with a longest span of 59 ft (18 m) and a deck 30 ft wide.

Who owns CO Road 643 over Paint River?

It is owned by the County Highway Agency.