US Bridges

18 1/2 Mile Road over I-94

Fair

Calhoun County, Michigan · 3.4 MI E of I-69 · Structure no. 000000000001277

Built
1960
65 years old
Condition
Fair
inspected August 2023
Type
Tee Beam
Concrete Continuous
Length
227 ft
4 main spans
Daily traffic
410
1974 count
Owner
State
State Highway Agency

About this bridge

18 1/2 Mile Road over I-94 is a concrete continuous tee beam carrying 18 1/2 Mile Road over I-94 in Calhoun County, Michigan. It was built in 1960, so it is 65 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 410 vehicles a day, roughly 3% of them trucks, projected to reach 410 by 1977. The structure is 227 ft (69.2 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries18 1/2 Mile Road
CrossesI-94
Location3.4 MI E of I-69
RouteCounty Highway 0
CountyCalhoun County
StateMichigan
Coordinates42.28222, -84.93637
Functional classUrban Local

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.
Substructure7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to 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 rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length227 ft (69.2 m)
Longest span71 ft (21.6 m)
Deck width31 ft (9.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic410 (1974)
Projected traffic410 by 1977
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
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 proposedDeck replacement with only incidental widening
Estimated improvement cost$94,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was 18 1/2 Mile Road over I-94 built?

It was built in 1960, making it 65 years old in 2025.

What condition is 18 1/2 Mile Road over I-94 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 August 2023.

How much traffic does 18 1/2 Mile Road over I-94 carry?

About 410 vehicles per day (1974 count), of which roughly 3% are trucks.

How long is 18 1/2 Mile Road over I-94?

The structure is 227 ft (69.2 m) long with a longest span of 71 ft (21.6 m) and a deck 31 ft wide.

Who owns 18 1/2 Mile Road over I-94?

It is owned by the State Highway Agency.