US Bridges

M-99 NB over Skinner Drain

Fair

Eaton County, Michigan · 1.5 MI S of Holt RD · Structure no. 000000000002303

Built
1978
47 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
30 ft
1 main span
Daily traffic
4,238
2007 count
Owner
State
State Highway Agency

About this bridge

M-99 NB over Skinner Drain is a steel stringer/multi-beam or girder carrying M-99 NB over Skinner Drain in Eaton County, Michigan. It was built in 1978, so it is 47 years old, younger 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 4,238 vehicles a day, roughly 4% of them trucks, projected to reach 5,508 by 2018. The structure is 30 ft (9.1 m) long and 46 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesM-99 NB
CrossesSkinner Drain
Location1.5 MI S of Holt RD
RouteState Highway 99
CountyEaton County
StateMichigan
Coordinates42.61881, -84.62236
Functional classRural Minor Arterial

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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
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 geometry8: Equal to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating85 US tons
Inventory rating51 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length30 ft (9.1 m)
Longest span28 ft (8.6 m)
Deck width46 ft (14 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,238 (2007)
Projected traffic5,508 by 2018
Trucks4%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was M-99 NB over Skinner Drain built?

It was built in 1978, making it 47 years old in 2025.

What condition is M-99 NB over Skinner Drain 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 May 2023.

How much traffic does M-99 NB over Skinner Drain carry?

About 4,238 vehicles per day (2007 count), of which roughly 4% are trucks.

How long is M-99 NB over Skinner Drain?

The structure is 30 ft (9.1 m) long with a longest span of 28 ft (8.6 m) and a deck 46 ft wide.

Who owns M-99 NB over Skinner Drain?

It is owned by the State Highway Agency.