US Bridges

M-21|CORUNNA RD over I-75 NB

Good

Genesee County, Michigan · Near W Lts of Flint · Structure no. 000000000002499

Built
2009
16 years old
Condition
Good
inspected February 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
204 ft
2 main spans
Daily traffic
27,203
2007 count
Owner
State
State Highway Agency

About this bridge

M-21|CORUNNA RD over I-75 NB is a prestressed concrete stringer/multi-beam or girder carrying M-21|CORUNNA RD over I-75 NB in Genesee County, Michigan. It was built in 2009, so it is 16 years old, younger than the Michigan average of 48.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 27,203 vehicles a day, roughly 1% of them trucks, projected to reach 24,000 by 2028. The structure is 204 ft (62.3 m) long and 94 ft wide.

Location

Open in Google Maps
CarriesM-21|CORUNNA RD
CrossesI-75 NB
LocationNear W Lts of Flint
RouteState Highway 21
CountyGenesee County
StateMichigan
Coordinates43.00214, -83.74937
Functional classUrban Other Principal Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating81.8 US tons
Inventory rating39.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHL 93
Structure length204 ft (62.3 m)
Longest span106 ft (32.4 m)
Deck width94 ft (28.5 m)
Roadway width76 ft (23.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27,203 (2007)
Projected traffic24,000 by 2028
Trucks1%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes

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 M-21|CORUNNA RD over I-75 NB built?

It was built in 2009, making it 16 years old in 2025.

What condition is M-21|CORUNNA RD over I-75 NB in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2024.

How much traffic does M-21|CORUNNA RD over I-75 NB carry?

About 27,203 vehicles per day (2007 count), of which roughly 1% are trucks.

How long is M-21|CORUNNA RD over I-75 NB?

The structure is 204 ft (62.3 m) long with a longest span of 106 ft (32.4 m) and a deck 94 ft wide.

Who owns M-21|CORUNNA RD over I-75 NB?

It is owned by the State Highway Agency.