Structure 8075 · Oakland County, MI

I-75 Access Ramps over I-75

Carries I-75 Access Ramps over I-75, In Troy.

Overall conditionGood

Set by its lowest-rated component: Deck at 7 of 9.

How ratings work
Decksets the rating7/9 · Good
Superstructure8/9 · Very Good
Substructure8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT207 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9 · sets the ratingSuperstructure 8/9Substructure 8/9

207 ft end to end, longest span 108 ft: about 3 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built20197 years old
Length207.0 ft63.1 m
Daily traffic—reported figure implausible
Last inspectedSeptember 2023every 24 months

Location

StateMichigan
CountyOakland
LocationIn Troy
CarriesI-75 Access Ramps
CrossesI-75
Coordinates42.59953, -83.16254

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length207.0 ft (63.1 m)
Max Span108.3 ft (33 m)
Deck Width55.4 ft (16.9 m)
Deck Area1066.4 sq m
Main Spans2
Year Built2019

Traffic

Avg Daily Traffic123,600 (2008)
That is about 61,800 vehicles per lane per day — beyond what any U.S. road carries (the busiest freeways run about 25,000–30,000). It is almost certainly a data-entry error in the National Bridge Inventory, so we leave this bridge out of traffic rankings.
Truck Traffic7%
Lanes On Bridge2
Lanes Under Bridge9

Inspection & Ownership

Last InspectionSeptember 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number000000000008075

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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